ANSYS流固耦合分析实例
ANSYS流固耦合计算实例
ANSYS流固耦合计算实例Oscillating Plate with Two-Way Fluid-Structure InteractionIntroductionThis tutorial includes:, Features, Overview of the Problem to Solve, Setting up the Solid Physics in Simulation (ANSYS Workbench), Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-Pre, Obtaining a Solution using ANSYS CFX-Solver Manager, Viewing Results in ANSYS CFX-PostIf this is the first tutorial you are working with, it is important to review the following topicsbefore beginning:, Setting the Working Directory, Changing the Display ColorsUnless you plan on running a session file, you should copy the sample files used in this tutorial from the installation folder for your software (<CFXROOT>/examples/) to your working directory. This prevents you from overwriting source files provided with your installation. If youplan to use a session file, please refer to Playing a Session File. Sample files referenced by this tutorial include:, OscillatingPlate.pre, OscillatingPlate.agdb, OscillatingPlate.gtm, OscillatingPlate.inp1. FeaturesThis tutorial addresses the following features of ANSYS CFX. Component Feature DetailsUser Mode General ModeANSYS CFX-Pre TransientSimulation TypeANSYS Multi-fieldComponent Feature DetailsFluid Type General FluidDomain Type Single DomainTurbulence Model LaminarHeat Transfer NoneMonitor Points Output ControlTransient Results FileWall: Mesh Motion = ANSYS MultiFieldBoundary Details Wall: No SlipWall: AdiabaticTimestep TransientAnimationANSYS CFX-Post Plots ContourVectorIn this tutorial you will learn about:, Moving mesh, Fluid-solid interaction (including modeling solid deformationusing ANSYS), Running an ANSYS Multi-field (MFX) simulation, Post-processing two results files simultaneously.2. Overview of the Problem to SolveThis tutorial uses a simple oscillating plate example to demonstrate how to set up and run a simulation involving two-way Fluid-Structure Interaction, where the fluid physics is solved in ANSYS CFX and thesolid physics is solved in the FEA package ANSYS. Coupling between the two solvers is required throughout the solution to model the interaction between fluid and solid as time progresses, and the framework for the coupling is provided by the ANSYS Multi-field solver, using the MFX setup.The geometry consists of a 2D closed cavity. A thin plate is anchored to the bottom of the cavity as shown below:An initial pressure of 100 Pa is applied to one side of the thin plate for 0.5 seconds in order to distort it. Once this pressure isreleased, the plate oscillates backwards and forwards as it attempts to regain its equilibrium (vertical) position. The surrounding fluid damps the oscillations, which therefore have an amplitude that decreases in time. The CFX Solver calculates how the fluid responds to the motion of the plate, and the ANSYS Solver calculates how the plate deforms as a result of both the initial applied pressure and the pressure resulting from the presence of the fluid. Coupling between the two solvers is required since the solid deformation affects the fluid solution, and the fluid solution affects the solid deformation.The tutorial describes the setup and execution of the calculation including the setup of the solid physics in Simulation (within ANSYS Workbench) and the setup of the fluid physics and ANSYS Multi-field settings in ANSYS CFX-Pre. If you do not have ANSYS Workbench, then you can use the provided ANSYS input file to avoid the need for Simulation.3. Setting up the Solid Physics in Simulation (ANSYS Workbench)This section describes the step-by-step definition of the solid physics in Simulation within ANSYS Workbench that will result in the creation of an ANSYS input file OscillatingPlate.inp. If you prefer, you can instead use the provided OscillatingPlate.inp file and continue from Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-Pre.Creating a New Simulation1. If required, launch ANSYS Workbench.2. Click Empty Project. The Project page appears displaying an unsaved project.3. Select File > Save or click Save button.4. If required, set the path location to a different folder. The default location is your workingdirectory. However, if you have a specific folder that you want to use to store files createdduring this tutorial, change the path.5. Under File name, type OscillatingPlate.6. Click Save.7. Under Link to Geometry File on the left hand task bar click Browse. Select the providedfile OscillatingPlate.agdb and click Open.8. Make sure that OscillatingPlate.agdb is highlighted and click New simulation from theleft-hand taskbar.Creating the Solid Material1. When Simulation opens, expand Geometry in the project tree at the left hand side of theSimulation window.2. Select Solid, and in the Details view below, select Material.3. Use the arrow that appears next to the material name Structural Steel to select NewMaterial.4. When the Engineering Data window opens, right-click New Material from the tree viewand rename it to Plate.5. Enter 2.5e06 for Young's Modulus, 0.35 for Poisson's Ratio and 2550 for Density.Note that the other properties are not used for this simulation, and that the units for thesevalues are implied by the global units in Simulation.6. Click the Simulation tab near the top of the Workbench window to return to thesimulation.Basic Analysis SettingsThe ANSYS Multi-field simulation is a transient mechanical analysis, with a timestep of 0.1 sand a time duration of 5 s.1. Select New Analysis > Flexible Dynamic from the toolbar.2. Select Analysis Settings from the tree view and in the Details view below, set Auto TimeStepping to Off.3. Set Time Step to 0.1.4. Under Tabular Data at the bottom right of the window, set End Time to5.0 for theSteps = 1 setting.Inserting LoadsLoads are applied to an FEA analysis as the equivalent of boundary conditions in ANSYS CFX. In this section, you will set a fixed support, a fluid-solid interface, and a pressure load. Fixed SupportThe fixed support is required to hold the bottom of the thin plate in place.1. Right-click Flexible Dynamic in the tree and select Insert > Fixed Support from theshortcut menu.2. Rotate the geometry using the Rotate button so that the bottom (low-y) face of thesolid is visible, then select Face and click the low-y face.That face should be highlighted to indicate selection.3. Ensure Fixed Support is selected in the Outline view, then, in the Details view, selectGeometry and click 1 Face to make the Apply button appear (if necessary). Click Applyto set the fixed support.Fluid-Solid InterfaceIt is necessary to define the region in the solid that defines the interface between the fluid in CFX and the solid in ANSYS. Data is exchanged across this interface during the execution of the simulation.1. Right-click Flexible Dynamic in the tree and select Insert >Fluid Solid Interface fromthe shortcut menu.2. Using the same face-selection procedure described earlier, select the three faces of thegeometry that form the interface between the solid and the fluid (low-x, high-y and high-xfaces) by holding down <Ctrl> to select multiple faces. Note thatthis load isautomatically given an interface number of 1.Pressure LoadThe pressure load provides the initial additional pressure of 100 [Pa] for the first 0.5 seconds of the simulation. It is defined using a step function.1. Right-click Flexible Dynamic in the tree and select Insert > Pressure from the shortcutmenu.2. Select the low-x face for Geometry.3. In the Details view, select Magnitude, and using the arrow that appears, select Tabular(Time).4. Under Tabular Data, set a pressure of 100 in the table row corresponding to a time of 0.[s] and [Pa], Note: The units for time and pressure in this tableare the global units of respectively.5. You now need to add two new rows to the table. This can be doneby typing the new timeand pressure data into the empty row at the bottom of the table, and Simulation willautomatically re-order the table in order of time value. Enter a pressure of 100 for a timevalue of 0.499, and a pressure of 0 for a time value of 0.5.This gives a step function for pressure that can be seen in thechart to the left of the table. Writing the ANSYS Input File The Simulation settings are now complete. An ANSYS Multi-field run cannot be launched from within Simulation, so the Solve buttons cannot be used to obtain a solution.1. Instead, highlight Solution in the tree, select Tools > Write ANSYS Input File andchoose to write the solution setup to the file OscillatingPlate.inp.2. The mesh is automatically generated as part of this process. If you want to examine it,select Mesh from the tree.3. Save the Simulation database, use the tab near the top of the Workbench window to returnto the Oscillating Plate [Project] tab, and save the project itself.4. Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-PreThis section describes the step-by-step definition of the flow physics and ANSYS Multi-field settings in ANSYS CFX-Pre.Playing a Session FileIf you want to skip past these instructions and to have ANSYS CFX-Pre set up the simulation automatically, you can select Session > Play Tutorial from the menu in ANSYS CFX-Pre, thenrun the session file: OscillatingPlate.pre. After you have playedthe session file as described in earlier tutorials under Playing the Session File and Starting ANSYS CFX-Solver Manager, proceed to Obtaining a Solution using ANSYS CFX-Solver Manager.Creating a New Simulation1. Start ANSYS CFX-Pre.2. Select File > New Simulation.3. Select General and click OK.4. Select File > Save Simulation As.5. Under File name, type OscillatingPlate.6. Click Save.Importing the Mesh1. Right-click Mesh and select Import Mesh.2. Select the provided mesh file, OscillatingPlate.gtm and click Open.Note:The file that was just created in Simulation,OscillatingPlate.inp, will be used as an input file for the ANSYS Solver.Setting the Simulation TypeA transient ANSYS Multi-field run executes as a series of timesteps. The Simulation Typetab is used both to enable an ANSYS Multi-field run and to specifythe time-related settings for it (in the External Solver Coupling settings). The ANSYS input file is read by ANSYS CFX-Pre so that it knows which Fluid Solid Interfaces are available.Once the timesteps and time duration are specified for the ANSYSMulti-field run (coupling run), ANSYS CFX automatically picks up these settings and it is not possible to set the timestep and time duration independently. Hence the only option available for Time Duration is CouplingTime Duration, and similarly for the related settings Time Step and Initial Time.1. Click Simulation Type .2. Apply the following settingsTab Setting ValueExternal Solver Coupling > Option ANSYS MultiFieldOscillatingPlate.inpExternal Solver Coupling > ANSYS Input File[a]Coupling Time Control > Coupling Time Duration > Total 5 [s] Time BasicCoupling Time Control > Coupling Time Steps > Option Timesteps SettingsCoupling Time Control > Coupling Time Steps > Timesteps 0.1 [s] Simulation Type > Option TransientSimulation Type > Time Duration > Option Coupling Time Duration Simulation Type > Time Steps > Option Coupling Time StepsSimulation Type > Initial Time > Option Coupling Initial Time[a] This file is located in your working directory.3. Click OK.Note:You may see a physics validation message related to the difference in the units used inANSYS CFX-Pre and the units contained within the ANSYS input file. While it is important toreview the units used in any simulation, you should be aware that, in this specific case, themessage is not crucial as it is related to temperature units and there is no heat transfer in this case.Therefore, this specific tutorial will not be affected by the physics message.Creating the FluidA custom fluid is created with user-specified properties. 1. Click Material .2. Set the name of the new material to Fluid.3. Apply the following settingsTab Setting ValueOption Pure SubstanceBasic Settings Thermodynamic State (Selected)Thermodynamic State > Thermodynamic State LiquidMaterial Properties Equation of State > Molar Mass 1 [kg kmol^-1] Tab Setting ValueEquation of State > Density 1 [kg m^-3]Transport Properties > Dynamic Viscosity (Selected)Transport Properties > Dynamic Viscosity > Dynamic 0.2 [Pa s] Viscosity4. Click OK.Creating the DomainIn order to allow the ANSYS Solver to communicate mesh displacements to the CFX Solver, mesh motion must be activated in CFX.1. Right click Simulation in the Outline tree view and ensure that Automatic DefaultDomain is selected. A domain named Default Domain should now appear under theSimulation branch.2. Double click Default Domain and apply the following settingsTab Setting ValueFluids List FluidGeneral Options Domain Models > Pressure > Reference Pressure 1 [atm] Domain Models > Mesh Deformation > Option Regions of MotionSpecifiedHeat Transfer > Option NoneFluid ModelsTurbulence > Option None (Laminar)3. Click OK.Creating the Boundary ConditionsIn addition to the symmetry conditions, another type of boundary condition corresponding with the interaction between the solid and the fluid is required in this tutorial.Fluid Solid External BoundaryThe interface between ANSYS and CFX is defined as an externalboundary in CFX that has its mesh displacement being defined by the ANSYS Multi-field coupling process.When an ANSYS Multi-field specification is being made in ANSYS CFX-Pre, it is necessary to provide the name and number of the matchingFluid Solid Interface that was created inSimulation. Since the interface number in Simulation was 1, the namein question is FSIN_1. (If the interface number had been 2, then thename would have been FSIN_2, and so on.)On this boundary, CFX will send ANSYS the forces on the interface, and ANSYS will sendback the total mesh displacement it calculates given the forces passed from CFX and the otherdefined loads.1. Create a new boundary condition named Interface.2. Apply the following settingsTab Setting ValueBoundary Type Wall Basic SettingsLocation InterfaceMesh Motion > Option ANSYS MultiFieldMesh Motion > Receive From ANSYS Total Mesh DisplacementBoundary DetailsMesh Motion > ANSYS Interface FSIN_1Mesh Motion > Send to ANSYS Total Force3. Click OK.Symmetry BoundariesSince a 2D representation of the flow field is being modeled (using a 3D mesh with oneelement thickness in the Z direction) symmetry boundaries will be created on the low and high Z2D regions of the mesh.1. Create a new boundary condition named Sym1.2. Apply the following settingsTab Setting ValueBoundary Type SymmetryBasic SettingsLocation Sym13. Click OK.4. Create a new boundary condition named Sym2.5. Apply the following settingsTab Setting ValueBoundary Type Symmetry Basic SettingsLocation Sym26. Click OK.Setting Initial ValuesSince a transient simulation is being modeled, initial values are required for all variables.1. Click Global Initialization .2. Apply the following settings:Tab Setting ValueInitial Conditions > Cartesian Velocity 0 [m s^-1] Components > U Initial Conditions > Cartesian Velocity 0 [m s^-1] Components > V GlobalSettings Initial Conditions > Cartesian Velocity 0 [m s^-1] Components > WInitial Conditions > Static Pressure > Relative 0 [Pa] Pressure3. Click OK.Setting Solver ControlVarious ANSYS Multi-field settings are contained under SolverControl under the ExternalCoupling tab. Most of these settings do not need to be changed forthis simulation.Within each timestep, a series of “coupling” or “stagger” iterations are performed to ensure that CFX, ANSYS and the data exchanged between the two solvers are all consistent. Within eachstagger iteration, ANSYS and CFX both run once each, but which one runs first is a user-specifiable setting. In general, it is slightly more efficient to choose the solver that drives the simulation to run first. In this case, the simulation is being driven by the initial pressure applied in ANSYS, so ANSYS is set to solve before CFX within eachstagger iteration.1. Click Solver Control .2. Apply the following settings:Tab Setting ValueSecond Order Transient Scheme > Option Backward EulerConvergence Control > Minimum Number of (Selected) Basic Coefficient Loops SettingsConvergence Control > Minimum Number of [a]2 Coefficient Loops > Min. Coeff. LoopsConvergence Control > Max. Coeff. Loops 3External Coupling Step Control > Solution Sequence Before CFX Fields Coupling Control > Solve ANSYS FieldsTab Setting Value[a] This setting is optional. The default value of 1 is also acceptable. 3. Click OK.Setting Output ControlThis step sets up transient results files to be written at set intervals.1. Click Output Control .2. On the Trn Results tab, create a new transient result with the default name.3. Apply the following settings to Transient Results 1:Setting ValueOption Selected VariablesOutput Variable List Pressure, Total Mesh Displacement, Velocity[a]Output Frequency > Option Every Coupling Step[a] This setting writes a transient results file every multi-field timestep. 4. Click the Monitor tab.5. Select Monitor Options.6. Under Monitor Points and Expressions:7. Click Add new item and accept the default name. 8. Set Option to Cartesian Coordinates. 9. Set Output Variables List to Total Mesh Displacement X. 10. Set Cartesian Coordinates to [0, 1, 0].11. Click OK.Writing the Solver (.def) File1. Click Write Solver File .2. If the Physics Validation Summary dialog box appears, click Yes to proceed.3. Apply the following settingsSetting ValueFile name OscillatingPlate.def[a]Quit CFX–Pre (Selected)[a] If using ANSYS CFX-Pre in Standalone Mode.4. Ensure Start Solver Manager is selected and click Save.5. If you are notified the file already exists, click Overwrite.6. This file is provided in the tutorial directory and will exist in your working folder if youhave copied it there.7. Quit ANSYS CFX-Pre, saving the simulation (.cfx) file at your discretion.5. Obtaining a Solution using ANSYS CFX-Solver ManagerThe execution of an ANSYS Multi-field simulation requires both the CFX and ANSYS solvers to be running and communicating with each other. ANSYS CFX-Solver Manager can be used to launch both solvers and to monitor the output from both.1. Ensure the Define Run dialog box is displayed.There is a new MultiField tab which contains settings specific for an ANSYS Multi-field simulation.2. On the MultiField tab, check that the ANSYS input file locationis correct (the location isrecorded in the definition file but may need to be changed if you have moved filesaround).3. On UNIX systems, you may need to manually specify where the ANSYS installation is ifit is not in the default location. In this case, you must providethe path to the v110/ansysdirectory.4. Click Start Run.The run begins by some initial processing of the ANSYS Multi-field input which results in the creation of a file containing the necessary multi-field commands for ANSYS, and then the ANSYS Solver is started. The CFX Solver is then started in such a way that it knows how to communicate with the ANSYS Solver.After the run is under way, two new plots appear in ANSYS CFX-Solver Manager:ANSYS Field Solver (Structural) This plot is produced only when the solid physics is set to use large displacements or when other non-linear analyses are performed. It shows convergence of the ANSYS Solver. Full details of the quantities are described in the ANSYS user documentation. In general, the CRIT quantities are the convergence criteria for each relevant variable, and the L2 quantities represent the L2 Norm of therelevant variable. For convergence, the L2 Norm should be below the criteria. The x-axis of the plot is the cumulative iteration number for ANSYS, which does not correspond to either timesteps or stagger iterations. Several ANSYS iterations will beperformed for each timestep, depending on how quickly ANSYS converges. You will usually see a somewhat “spiky” plot, as each quantity will be unconverged at the start of each timestep, and then convergence will improve.ANSYS Interface Loads (Structural) This plot shows the convergencefor each quantitythat is part of the data exchanged between the CFX and ANSYS Solvers. In this case, four lines appear, corresponding to two force components (FX and FY) and two displacement components (UX and UY). Since the analysis is 2D, FZ and UZ are not exchanged. Each quantity is converged when the plot shows a negative value. The x-axis of the plot corresponds to the cumulative number of stagger iterations (coupling iterations) and there are several of these for every timestep. Again, a spiky plot is expected as the quantities will not be converged at the start of a timestep.The ANSYS out file is displayed in ANSYS CFX-Solver Manager as an extra tab. Similar to the CFX out file, this is a text file recording output from ANSYS as the solution progresses.1. Click the User Points tab and watch how the top of the plate displaces as the solutiondevelops.2. When the solvers have finished and ANSYS CFX-Solver Manager puts up a dialog boxto tell you this, click Yes to post-process the results.3. If using Standalone Mode, quit ANSYS CFX-Solver Manager.6. Viewing Results in ANSYS CFX-PostFor an ANSYS Multi-field run, both the CFX and ANSYS results files will be opened up in ANSYS CFX-Post by default if ANSYS CFX-Post is started from a finished run in ANSYS CFX-Solver Manager.Plotting Results on the SolidWhen ANSYS CFX-Post reads an ANSYS results file, all the ANSYS variables are available to plot on the solid, including stresses and strains. The mesh regions available for plots by default are limited to the full boundary of the solid, plus certain named regions which are automatically created when particular types of load are added in Simulation. For example, any Fluid Solid Interface will have a corresponding mesh region with a name such as FSIN 1. In this case, there is also a named region corresponding to the location of the fixed support, but in general pressure loads do not result in a named region.You can add extra mesh regions for plotting by creating named selections in Simulation - see the Simulation product documentation for more details. Note that the named selection must have a name which contains only English letters, numbers and underscores for the named mesh region to be successfully created.Note that when ANSYS CFX-Post loads an ANSYS results file, the true global range for each variable is not automatically calculated, as this would add a substantial amount of time onto how long it takes to load such a file (you can turn on this calculation using Edit > Options and using the Pre-calculate variable global ranges setting under CFX-Post > Files). When theglobal range is first used for plotting a variable, it is calculated as the range within the current timestep. As subsequent timesteps are loaded into ANSYS CFX-Post, the Global Range is extended each time variable values are found outside the previous Global Range.1. Turn on the visibility of Boundary ANSYS (under ANSYS > Domain ANSYS).2. Right-click a blank area in the viewer and select Predefined Camera > View Towards-Z. Zoom into the plate to see it clearly.3. Apply the following settings to Boundary ANSYS:Tab Setting ValueMode Variable ColorVariable Von Mises Stress4. Click Apply.5. Select Tools > Timestep Selector from the task bar to open the Timestep Selectordialog box. Notice that a separate list of timesteps is availablefor each results file loaded,although for this case the lists are the same. By default, Sync Cases is set to By TimeValue which means that each time you change the timestep for one results file, ANSYSCFX-Post will automatically load the results corresponding to the same time value for allother results files.6. Set Match to Nearest Available.7. Change to a time value of 1 [s] and click Apply.The corresponding transient results are loaded and you can see the mesh move in both the CFX and ANSYS regions.1. Clear the visibility check box of Boundary ANSYS.2. Create a contour plot, set Locations to Boundary ANSYS and Sym2, and set Variable toTotal Mesh Displacement. Click Apply.3. Using the timestep selector, load time value 1.1 [s] (which is where the maximum totalmesh displacement occurs).This verifies that the contours of Total Mesh Displacement are continuous through both the ANSYS and CFX regions.Many FSI cases will have only relatively small mesh displacements, which can make visualization of the mesh displacement difficult. ANSYS CFX-Post allows you to visually magnify the mesh deformation for ease of viewing such displacements. Although it is not strictly necessary forthis case, which has mesh displacements which are easily visible unmagnified, this is illustrated by the next few instructions.1. Using the timestep selector, load time value 0.1 [s] (which has a much smaller meshdisplacement than the currently loaded timestep).2. Place the mouse over somewhere in the viewer where the background color is showing.Right-click and select Deformation > Auto. Notice that the mesh displacements are nowexaggerated. The Auto setting is calculated to make the largest mesh displacement afixed percentage of the domain size.3. To return the deformations to their true scale, right-click and select Deformation > TrueScale.Creating an Animation1. Using the Timestep Selector dialog box, ensure the time value of 0.1 [s] is loaded.2. Clear the visibility check box of Contour 1.3. Turn on the visibility of Sym2.4. Apply the following settings to Sym2.Tab Setting ValueMode Variable ColorVariable Pressure5. Click Apply.6. Create a vector plot, set Locations to Sym1 and leave Variable set to Velocity. SetColor to be Constant and choose black. Click Apply.7. Select the visibility check box of Boundary ANSYS, and set Color to a constant blue.8. Click Animation .The Animation dialog box appears.9. Select Keyframe Animation.10. In the Animation dialog box:a. Click New to create KeyframeNo1.b. Highlight KeyframeNo1, then change # of Frames to 48.c. Load the last timestep (50) using the timestep selector.d. Click New to create KeyframeNo2.The # of Frames parameter has no effect for the last keyframe, so leave it at thedefault value.e. Select Save MPEG.f. Click Browse next to the MPEG file data box to set a path and file name forthe MPEG file.。
ansys workbench 流固耦合计算实例
Oscillating Plate with Two-Way Fluid-Structure InteractionIntroductionThis tutorial includes:•Features•Overview of the Problem to Solve•Setting up the Solid Physics in Simulation (ANSYS Workbench)•Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-Pre•Obtaining a Solution using ANSYS CFX-Solver Manager•Viewing Results in ANSYS CFX-PostIf this is the first tutorial you are working with, it is important to review the following topics before beginning:•Setting the Working Directory•Changing the Display ColorsUnless you plan on running a session file, you should copy the sample files used in this tutorial from the installation folder for your software (<CFXROOT>/examples/) to your working directory. This prevents you from overwriting source files provided with your installation. If you plan to use a session file, please refer to Playing a Session File.Sample files referenced by this tutorial include:•OscillatingPlate.pre•OscillatingPlate.agdb•OscillatingPlate.gtm•OscillatingPlate.inp1.FeaturesThis tutorial addresses the following features of ANSYS CFX.In this tutorial you will learn about:•Moving mesh•Fluid-solid interaction (including modeling solid deformation using ANSYS)•Running an ANSYS Multi-field (MFX) simulation•Post-processing two results files simultaneously.2.Overview of the Problem to SolveThis tutorial uses a simple oscillating plate example to demonstrate how to set up and run a simulation involving two-way Fluid-Structure Interaction, where the fluid physics is solved in ANSYS CFX and the solid physics is solved in the FEA package ANSYS. Coupling between the two solvers is required throughout the solution to model the interaction between fluid and solid as time progresses, and the framework for the coupling is provided by the ANSYS Multi-field solver, using the MFX setup.The geometry consists of a 2D closed cavity. A thin plate is anchored to the bottom of the cavity as shown below:An initial pressure of 100 Pa is applied to one side of the thin plate for 0.5 seconds in order to distort it. Once this pressure is released, the plate oscillates backwards and forwards as it attempts to regain its equilibrium (vertical) position. The surrounding fluid damps the oscillations, which therefore have an amplitude that decreases in time. The CFX Solver calculates how the fluid responds to the motion of the plate, and the ANSYS Solver calculates how the plate deforms as a result of both the initial applied pressure and the pressure resulting from the presence of the fluid. Coupling between the two solvers is required since the solid deformation affects the fluid solution, and the fluid solution affects the solid deformation.The tutorial describes the setup and execution of the calculation including the setup of the solid physics in Simulation (within ANSYS Workbench) and the setup of the fluid physics and ANSYS Multi-field settings in ANSYS CFX-Pre. If you do not have ANSYS Workbench, then you can use the provided ANSYS input file to avoid the need for Simulation.3.Setting up the Solid Physics in Simulation (ANSYS Workbench)This section describes the step-by-step definition of the solid physics in Simulation within ANSYS Workbench that will result in the creation of an ANSYS input file OscillatingPlate.inp. If you prefer, you can instead use the provided OscillatingPlate.inp file and continue from Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-Pre.Creating a New Simulation1.If required, launch ANSYS Workbench.2.Click Empty Project. The Project page appears displaying an unsaved project.3.Select File > Save or click Save button.4.If required, set the path location to a different folder. The default location is your workingdirectory. However, if you have a specific folder that you want to use to store files created during this tutorial, change the path.5.Under File name, type OscillatingPlate.6.Click Save.7.Under Link to Geometry File on the left hand task bar click Browse. Select the providedfile OscillatingPlate.agdb and click Open.8.Make sure that OscillatingPlate.agdb is highlighted and click New simulation from theleft-hand taskbar.Creating the Solid Material1.When Simulation opens, expand Geometry in the project tree at the left hand side of theSimulation window.2.Select Solid, and in the Details view below, select Material.e the arrow that appears next to the material name Structural Steel to select NewMaterial.4.When the Engineering Data window opens, right-click New Material from the tree viewand rename it to Plate.5.Enter 2.5e06 for Young's Modulus, 0.35 for Poisson's Ratio and 2550 for Density.Note that the other properties are not used for this simulation, and that the units for these values are implied by the global units in Simulation.6.Click the Simulation tab near the top of the Workbench window to return to thesimulation.Basic Analysis SettingsThe ANSYS Multi-field simulation is a transient mechanical analysis, with a timestep of 0.1 s and a time duration of 5 s.1.Select New Analysis > Flexible Dynamic from the toolbar.2.Select Analysis Settings from the tree view and in the Details view below, set Auto TimeStepping to Off.3.Set Time Step to 0.1.4.Under Tabular Data at the bottom right of the window, set End Time to5.0 for theSteps = 1 setting.Inserting LoadsLoads are applied to an FEA analysis as the equivalent of boundary conditions in ANSYS CFX. In this section, you will set a fixed support, a fluid-solid interface, and a pressure load. Fixed SupportThe fixed support is required to hold the bottom of the thin plate in place.1.Right-click Flexible Dynamic in the tree and select Insert> Fixed Support from theshortcut menu.2.Rotate the geometry using the Rotate button so that the bottom (low-y) face of thesolid is visible, then select Face and click the low-y face.That face should be highlighted to indicate selection.3.Ensure Fixed Support is selected in the Outline view, then, in the Details view, selectGeometry and click 1 Face to make the Apply button appear (if necessary). Click Apply to set the fixed support.Fluid-Solid InterfaceIt is necessary to define the region in the solid that defines the interface between the fluid in CFX and the solid in ANSYS. Data is exchanged across this interface during the execution of the simulation.1.Right-click Flexible Dynamic in the tree and select Insert > Fluid Solid Interface fromthe shortcut menu.ing the same face-selection procedure described earlier, select the three faces of thegeometry that form the interface between the solid and the fluid (low-x, high-y and high-x faces) by holding down <Ctrl> to select multiple faces. Note that this load is automatically given an interface number of 1.Pressure LoadThe pressure load provides the initial additional pressure of 100 [Pa] for the first 0.5 seconds of the simulation. It is defined using a step function.1.Right-click Flexible Dynamic in the tree and select Insert > Pressure from the shortcutmenu.2.Select the low-x face for Geometry.3.In the Details view, select Magnitude, and using the arrow that appears, select Tabular(Time).4.Under Tabular Data, set a pressure of 100 in the table row corresponding to a time of 0.Note: The units for time and pressure in this table are the global units of [s]and [Pa], respectively.5.You now need to add two new rows to the table. This can be done by typing the new timeand pressure data into the empty row at the bottom of the table, and Simulation will automatically re-order the table in order of time value. Enter a pressure of 100 for a time value of 0.499, and a pressure of 0 for a time value of 0.5.This gives a step function for pressure that can be seen in the chart to the left of the table. Writing the ANSYS Input FileThe Simulation settings are now complete. An ANSYS Multi-field run cannot be launched from within Simulation, so the Solve buttons cannot be used to obtain a solution.1.Instead, highlight Solution in the tree, select Tools> Write ANSYS Input File andchoose to write the solution setup to the file OscillatingPlate.inp.2.The mesh is automatically generated as part of this process. If you want to examine it,select Mesh from the tree.3.Save the Simulation database, use the tab near the top of the Workbench window to returnto the Oscillating Plate [Project] tab, and save the project itself.4.Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-PreThis section describes the step-by-step definition of the flow physics and ANSYS Multi-field settings in ANSYS CFX-Pre.Playing a Session FileIf you want to skip past these instructions and to have ANSYS CFX-Pre set up the simulation automatically, you can select Session > Play Tutorial from the menu in ANSYS CFX-Pre, then run the session file: OscillatingPlate.pre. After you have played the session file as described in earlier tutorials under Playing the Session File and Starting ANSYS CFX-Solver Manager, proceed to Obtaining a Solution using ANSYS CFX-Solver Manager.Creating a New Simulation1.Start ANSYS CFX-Pre.2.Select File > New Simulation.3.Select General and click OK.4.Select File > Save Simulation As.5.Under File name, type OscillatingPlate.6.Click Save.Importing the Mesh1.Right-click Mesh and select Import Mesh.2.Select the provided mesh file, OscillatingPlate.gtm and click Open.Note：The file that was just created in Simulation, OscillatingPlate.inp, will be used as an input file for the ANSYS Solver.Setting the Simulation TypeA transient ANSYS Multi-field run executes as a series of timesteps. The Simulation Type tab is used both to enable an ANSYS Multi-field run and to specify the time-related settings for it (in the External Solver Coupling settings). The ANSYS input file is read by ANSYS CFX-Pre so that it knows which Fluid Solid Interfaces are available.Once the timesteps and time duration are specified for the ANSYS Multi-field run (coupling run), ANSYS CFX automatically picks up these settings and it is not possible to set the timestep and time duration independently. Hence the only option available for Time Duration is Coupling Time Duration, and similarly for the related settings Time Step and Initial Time.1.Click Simulation Type .2.Apply the following settingsTab Setting ValueBasic Settings External Solver Coupling > Option ANSYS MultiField External Solver Coupling > ANSYS Input FileOscillatingPlate.inp[a]Coupling Time Control > Coupling Time Duration > TotalTime5 [s]Coupling Time Control > Coupling Time Steps > Option TimestepsCoupling Time Control > Coupling Time Steps > Timesteps 0.1 [s]Simulation Type > Option TransientSimulation Type > Time Duration > Option Coupling Time Duration Simulation Type > Time Steps > Option Coupling Time Steps Simulation Type > Initial Time > Option Coupling Initial Time[a] This file is located in your working directory.3.Click OK.Note：You may see a physics validation message related to the difference in the units used in ANSYS CFX-Pre and the units contained within the ANSYS input file. While it is important to review the units used in any simulation, you should be aware that, in this specific case, the message is not crucial as it is related to temperature units and there is no heat transfer in this case. Therefore, this specific tutorial will not be affected by the physics message.Creating the FluidA custom fluid is created with user-specified properties.1.Click Material .2.Set the name of the new material to Fluid.3.Apply the following settingsTab Setting ValueBasic Settings Option Pure Substance Thermodynamic State (Selected) Thermodynamic State > Thermodynamic State LiquidMaterial Properties Equation of State > Molar Mass 1 [kg kmol^-1]4.Click OK.Creating the DomainIn order to allow the ANSYS Solver to communicate mesh displacements to the CFX Solver, mesh motion must be activated in CFX.1.Right click Simulation in the Outline tree view and ensure that Automatic DefaultDomain is selected. A domain named Default Domain should now appear under the Simulation branch.2.Double click Default Domain and apply the following settings3.Click OK.Creating the Boundary ConditionsIn addition to the symmetry conditions, another type of boundary condition corresponding with the interaction between the solid and the fluid is required in this tutorial.Fluid Solid External BoundaryThe interface between ANSYS and CFX is defined as an external boundary in CFX that has its mesh displacement being defined by the ANSYS Multi-field coupling process.When an ANSYS Multi-field specification is being made in ANSYS CFX-Pre, it is necessary to provide the name and number of the matching Fluid Solid Interface that was created in Simulation. Since the interface number in Simulation was 1, the name in question is FSIN_1. (If the interface number had been 2, then the name would have been FSIN_2, and so on.)On this boundary, CFX will send ANSYS the forces on the interface, and ANSYS will send back the total mesh displacement it calculates given the forces passed from CFX and the other defined loads.1.Create a new boundary condition named Interface.2.Apply the following settings3.Click OK.Symmetry BoundariesSince a 2D representation of the flow field is being modeled (using a 3D mesh with one element thickness in the Z direction) symmetry boundaries will be created on the low and high Z 2D regions of the mesh.1.Create a new boundary condition named Sym1.2.Apply the following settings3.Click OK.4.Create a new boundary condition named Sym2.5.Apply the following settings6.Click OK.Setting Initial ValuesSince a transient simulation is being modeled, initial values are required for all variables.1.Click Global Initialization .2.Apply the following settings:Tab Setting ValueGlobal Settings Initial Conditions > Cartesian Velocity Components > U0 [m s^-1] Initial Conditions > Cartesian Velocity Components > V0 [m s^-1] Initial Conditions > Cartesian Velocity Components > W0 [m s^-1] Initial Conditions > Static Pressure > RelativePressure0 [Pa]3.Click OK.Setting Solver ControlVarious ANSYS Multi-field settings are contained under Solver Control under the External Coupling tab. Most of these settings do not need to be changed for this simulation.Within each timestep, a series of “coupling” or “stagger” iterations are performed to ensure that CFX, ANSYS and the data exchanged between the two solvers are all consistent. Within each stagger iteration, ANSYS and CFX both run once each, but which one runs first is a user-specifiable setting. In general, it is slightly more efficient to choose the solver that drives the simulation to run first. In this case, the simulation is being driven by the initial pressure applied in ANSYS, so ANSYS is set to solve before CFX within each stagger iteration.1.Click Solver Control .2.Apply the following settings:Tab Setting ValueBasic Settings Transient Scheme > OptionSecond OrderBackward Euler Convergence Control > Minimum Number ofCoefficient Loops(Selected) Convergence Control > Minimum Number ofCoefficient Loops > Min. Coeff. Loops2[a]Convergence Control > Max. Coeff. Loops 3External Coupling Coupling Step Control > Solution SequenceControl > Solve ANSYS FieldsBefore CFX FieldsTab Setting Value[a] This setting is optional. The default value of 1 is also acceptable.3.Click OK.Setting Output ControlThis step sets up transient results files to be written at set intervals.1.Click Output Control .2.On the Trn Results tab, create a new transient result with the default name.3.Apply the following settings to Transient Results 1:Setting ValueOption Selected VariablesOutput Variable List Pressure, Total Mesh Displacement, VelocityOutput Frequency > Option Every Coupling Step[a][a] This setting writes a transient results file every multi-field timestep.4.Click the Monitor tab.5.Select Monitor Options.6.Under Monitor Points and Expressions:7.Click Add new item and accept the default name.8.Set Option to Cartesian Coordinates.9.Set Output Variables List to Total Mesh Displacement X.10.Set Cartesian Coordinates to [0, 1, 0].11.Click OK.Writing the Solver (.def) File1.Click Write Solver File .2.If the Physics Validation Summary dialog box appears, click Yes to proceed.3.Apply the following settingsSetting ValueFile name OscillatingPlate.defQuit CFX–Pre[a](Selected)[a] If using ANSYS CFX-Pre in Standalone Mode.4.Ensure Start Solver Manager is selected and click Save.5.If you are notified the file already exists, click Overwrite.6.This file is provided in the tutorial directory and will exist in your working folder if youhave copied it there.7.Quit ANSYS CFX-Pre, saving the simulation (.cfx) file at your discretion.5.Obtaining a Solution using ANSYS CFX-Solver ManagerThe execution of an ANSYS Multi-field simulation requires both the CFX and ANSYS solvers to be running and communicating with each other. ANSYS CFX-Solver Manager can be used to launch both solvers and to monitor the output from both.1.Ensure the Define Run dialog box is displayed.There is a new MultiField tab which contains settings specific for an ANSYS Multi-field simulation.2.On the MultiField tab, check that the ANSYS input file location is correct (the location isrecorded in the definition file but may need to be changed if you have moved files around).3.On UNIX systems, you may need to manually specify where the ANSYS installation is ifit is not in the default location. In this case, you must provide the path to the v110/ansys directory.4.Click Start Run.The run begins by some initial processing of the ANSYS Multi-field input which results in the creation of a file containing the necessary multi-field commands for ANSYS, and then the ANSYS Solver is started. The CFX Solver is then started in such a way that it knows how to communicate with the ANSYS Solver.After the run is under way, two new plots appear in ANSYS CFX-Solver Manager:ANSYS Field Solver (Structural) This plot is produced only when the solid physics is set to use large displacements or when other non-linear analyses are performed. It shows convergence of the ANSYS Solver. Full details of the quantities are described in the ANSYS user documentation. In general, the CRIT quantities are the convergence criteria for each relevant variable, and the L2 quantities represent the L2 Norm of the relevant variable. For convergence, the L2 Norm should be below the criteria. The x-axis of the plot is the cumulative iteration number for ANSYS, which does not correspond to either timesteps or stagger iterations. Several ANSYS iterations will beperformed for each timestep, depending on how quickly ANSYS converges. You will usually see a somewhat “spiky” plot, as each quantity will be unconverged at the start of each timestep, and then convergence will improve.ANSYS Interface Loads (Structural)This plot shows the convergence for each quantity that is part of the data exchanged between the CFX and ANSYS Solvers. In this case, four lines appear, corresponding to two force components (FX and FY) and two displacement components (UX and UY). Since the analysis is 2D, FZ and UZ are not exchanged. Each quantity is converged when the plot shows a negative value. The x-axis of the plot corresponds to the cumulative number of stagger iterations (coupling iterations) and there are several of these for every timestep. Again, a spiky plot is expected as the quantities will not be converged at the start of a timestep.The ANSYS out file is displayed in ANSYS CFX-Solver Manager as an extra tab. Similar to the CFX out file, this is a text file recording output from ANSYS as the solution progresses.1.Click the User Points tab and watch how the top of the plate displaces as the solutiondevelops.2.When the solvers have finished and ANSYS CFX-Solver Manager puts up a dialog boxto tell you this, click Yes to post-process the results.3.If using Standalone Mode, quit ANSYS CFX-Solver Manager.6.Viewing Results in ANSYS CFX-PostFor an ANSYS Multi-field run, both the CFX and ANSYS results files will be opened up in ANSYS CFX-Post by default if ANSYS CFX-Post is started from a finished run in ANSYS CFX-Solver Manager.Plotting Results on the SolidWhen ANSYS CFX-Post reads an ANSYS results file, all the ANSYS variables are available to plot on the solid, including stresses and strains. The mesh regions available for plots by default are limited to the full boundary of the solid, plus certain named regions which are automatically created when particular types of load are added in Simulation. For example, any Fluid Solid Interface will have a corresponding mesh region with a name such as FSIN 1. In this case, there is also a named region corresponding to the location of the fixed support, but in general pressure loads do not result in a named region.You can add extra mesh regions for plotting by creating named selections in Simulation - see the Simulation product documentation for more details. Note that the named selection must have a name which contains only English letters, numbers and underscores for the named mesh region to be successfully created.Note that when ANSYS CFX-Post loads an ANSYS results file, the true global range for each variable is not automatically calculated, as this would add a substantial amount of time onto how long it takes to load such a file (you can turn on this calculation using Edit > Options and using the Pre-calculate variable global ranges setting under CFX-Post> Files). When the global range is first used for plotting a variable, it is calculated as the range within the current timestep. As subsequent timesteps are loaded into ANSYS CFX-Post, the Global Range is extended each time variable values are found outside the previous Global Range.1.Turn on the visibility of Boundary ANSYS (under ANSYS > Domain ANSYS).2.Right-click a blank area in the viewer and select Predefined Camera > View Towards-Z. Zoom into the plate to see it clearly.3.Apply the following settings to Boundary ANSYS:4.Click Apply.5.Select Tools> Timestep Selector from the task bar to open the Timestep Selectordialog box. Notice that a separate list of timesteps is available for each results file loaded, although for this case the lists are the same. By default, Sync Cases is set to By Time Value which means that each time you change the timestep for one results file, ANSYS CFX-Post will automatically load the results corresponding to the same time value for all other results files.6.Set Match to Nearest Available.7.Change to a time value of 1 [s] and click Apply.The corresponding transient results are loaded and you can see the mesh move in both the CFX and ANSYS regions.1.Clear the visibility check box of Boundary ANSYS.2.Create a contour plot, set Locations to Boundary ANSYS and Sym2, and set Variable toTotal Mesh Displacement. Click Apply.ing the timestep selector, load time value 1.1 [s] (which is where the maximum totalmesh displacement occurs).This verifies that the contours of Total Mesh Displacement are continuous through both the ANSYS and CFX regions.Many FSI cases will have only relatively small mesh displacements, which can make visualization of the mesh displacement difficult. ANSYS CFX-Post allows you to visually magnify the mesh deformation for ease of viewing such displacements. Although it is not strictly necessary for this case, which has mesh displacements which are easily visible unmagnified, this is illustrated by the next few instructions.ing the timestep selector, load time value 0.1 [s] (which has a much smaller meshdisplacement than the currently loaded timestep).2.Place the mouse over somewhere in the viewer where the background color is showing.Right-click and select Deformation > Auto. Notice that the mesh displacements are now exaggerated. The Auto setting is calculated to make the largest mesh displacement a fixed percentage of the domain size.3.To return the deformations to their true scale, right-click and select Deformation > TrueScale.Creating an Animationing the Timestep Selector dialog box, ensure the time value of 0.1 [s] is loaded.2.Clear the visibility check box of Contour 1.3.Turn on the visibility of Sym2.4.Apply the following settings to Sym2.5.Click Apply.6.Create a vector plot, set Locations to Sym1 and leave Variable set to Velocity. SetColor to be Constant and choose black. Click Apply.7.Select the visibility check box of Boundary ANSYS, and set Color to a constant blue.8.Click Animation .The Animation dialog box appears.9.Select Keyframe Animation.10.In the Animation dialog box:a.Click New to create KeyframeNo1.b.Highlight KeyframeNo1, then change # of Frames to 48.c.Load the last timestep (50) using the timestep selector.d.Click New to create KeyframeNo2.The # of Frames parameter has no effect for the last keyframe, so leave it at thedefault value.e.Select Save MPEG.f.Click Browse next to the MPEG file data box to set a path and file name forthe MPEG file.If the file path is not given, the file will be saved in the directory from whichANSYS CFX-Post was launched.g.Click Save.The MPEG file name (including path) will be set, but the MPEG will not becreated yet.h.Frame 1 is not loaded (The loaded frame is shown in the middle of theAnimation dialog box, beside F:). Click To Beginning to load it then waita few seconds for the frame to load.i.Click Play the animation .The MPEG will be created as the animation proceeds. This will be slow, since atimestep must be loaded and objects must be created for each frame. To view theMPEG file, you need to use a viewer that supports the MPEG format.11.When you have finished, exit ANSYS CFX-Post.。
ansysworkbench流固耦合计算实例
Oscillating Plate with Two-Way Fluid-Structure InteractionIntroductionThis tutorial includes:•Features•Overview of the Problem to Solve•Setting up the Solid Physics in Simulation (ANSYS Workbench)•Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-Pre•Obtaining a Solution using ANSYS CFX-Solver Manager•Viewing Results in ANSYS CFX-PostIf this is the first tutorial you are working with, it is important to review the following topics before beginning:•Setting the Working Directory•Changing the Display ColorsUnless you plan on running a session file, you should copy the sample files used in this tutorial from the installation folder for your software (<CFXROOT>/examples/) to your working directory. This prevents you from overwriting source files provided with your installation. If you plan to use a session file, please refer to Playing a Session File.Sample files referenced by this tutorial include:••••1.FeaturesThis tutorial addresses the following features of ANSYS CFX.In this tutorial you will learn about:•Moving mesh•Fluid-solid interaction (including modeling solid deformation using ANSYS)•Running an ANSYS Multi-field (MFX) simulation•Post-processing two results files simultaneously.2.Overview of the Problem to SolveThis tutorial uses a simple oscillating plate example to demonstrate how to set up and run a simulation involving two-way Fluid-Structure Interaction, where the fluid physics is solved in ANSYS CFX and the solid physics is solved in the FEA package ANSYS. Coupling between the two solvers is required throughout the solution to model the interaction between fluid and solid as time progresses, and the framework for the coupling is provided by the ANSYS Multi-field solver, using the MFX setup.The geometry consists of a 2D closed cavity. A thin plate is anchored to the bottom of the cavity as shown below:An initial pressure of 100 Pa is applied to one side of the thin plate for seconds in order to distort it. Once this pressure is released, the plate oscillates backwards and forwards as it attempts to regain its equilibrium (vertical) position. The surrounding fluid damps the oscillations, which therefore have an amplitude that decreases in time. The CFX Solver calculates how the fluid responds to the motion of the plate, and the ANSYS Solver calculates how the plate deforms as a result of both the initial applied pressure and the pressure resulting from the presence of the fluid. Coupling between the two solvers is required since the solid deformation affects the fluid solution, and the fluid solution affects the solid deformation.The tutorial describes the setup and execution of the calculation including the setup of the solid physics in Simulation (within ANSYS Workbench) and the setup of the fluid physics and ANSYS Multi-field settings in ANSYS CFX-Pre. If you do not have ANSYS Workbench, then you can use the provided ANSYS input file to avoid the need for Simulation.3.Setting up the Solid Physics in Simulation (ANSYS Workbench)This section describes the step-by-step definition of the solid physics in Simulation within ANSYS Workbench that will result in the creation of an ANSYS input file . If you prefer, you can instead use the provided file and continue from Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-Pre.Creating a New Simulation1.If required, launch ANSYS Workbench.2.Click Empty Project. The Project page appears displaying an unsaved project.3.Select File > Save or click Save button.4.If required, set the path location to a different folder. The default location is your workingdirectory. However, if you have a specific folder that you want to use to store files created during this tutorial, change the path.5.Under File name, type OscillatingPlate.6.Click Save.7.Under Link to Geometry File on the left hand task bar click Browse. Select the providedfile and click Open.8.Make sure that is highlighted and click New simulation from the left-hand taskbar. Creating the Solid Material1.When Simulation opens, expand Geometry in the project tree at the left hand side of theSimulation window.2.Select Solid, and in the Details view below, select Material.e the arrow that appears next to the material name Structural Steel to select NewMaterial.4.When the Engineering Data window opens, right-click New Material from the tree viewand rename it to Plate.5.Enter for Young's Modulus, for Poisson's Ratio and 2550 for Density.Note that the other properties are not used for this simulation, and that the units for these values are implied by the global units in Simulation.6.Click the Simulation tab near the top of the Workbench window to return to thesimulation.Basic Analysis SettingsThe ANSYS Multi-field simulation is a transient mechanical analysis, with a timestep of s and a time duration of 5 s.1.Select New Analysis > Flexible Dynamic from the toolbar.2.Select Analysis Settings from the tree view and in the Details view below, set Auto TimeStepping to Off.3.Set Time Step to .4.Under Tabular Data at the bottom right of the window, set End Time to for the Steps= 1 setting.Inserting LoadsLoads are applied to an FEA analysis as the equivalent of boundary conditions in ANSYS CFX. In this section, you will set a fixed support, a fluid-solid interface, and a pressure load. Fixed SupportThe fixed support is required to hold the bottom of the thin plate in place.1.Right-click Flexible Dynamic in the tree and select Insert> Fixed Support from theshortcut menu.2.Rotate the geometry using the Rotate button so that the bottom (low-y) face of thesolid is visible, then select Face and click the low-y face.That face should be highlighted to indicate selection.3.Ensure Fixed Support is selected in the Outline view, then, in the Details view, selectGeometry and click 1 Face to make the Apply button appear (if necessary). Click Apply to set the fixed support.Fluid-Solid InterfaceIt is necessary to define the region in the solid that defines the interface between the fluid in CFX and the solid in ANSYS. Data is exchanged across this interface during the execution of the simulation.1.Right-click Flexible Dynamic in the tree and select Insert > Fluid Solid Interface fromthe shortcut menu.ing the same face-selection procedure described earlier, select the three faces of thegeometry that form the interface between the solid and the fluid (low-x, high-y and high-x faces) by holding down <Ctrl> to select multiple faces. Note that this load is automatically given an interface number of 1.Pressure LoadThe pressure load provides the initial additional pressure of 100 [Pa] for the first seconds of the simulation. It is defined using a step function.1.Right-click Flexible Dynamic in the tree and select Insert > Pressure from the shortcutmenu.2.Select the low-x face for Geometry.3.In the Details view, select Magnitude, and using the arrow that appears, select Tabular(Time).4.Under Tabular Data, set a pressure of 100 in the table row corresponding to a time of 0.Note: The units for time and pressure in this table are the global units of [s]and [Pa], respectively.5.You now need to add two new rows to the table. This can be done by typing the new timeand pressure data into the empty row at the bottom of the table, and Simulation will automatically re-order the table in order of time value. Enter a pressure of 100 for a time value of , and a pressure of 0 for a time value of .This gives a step function for pressure that can be seen in the chart to the left of the table. Writing the ANSYS Input FileThe Simulation settings are now complete. An ANSYS Multi-field run cannot be launched from within Simulation, so the Solve buttons cannot be used to obtain a solution.1.Instead, highlight Solution in the tree, select Tools> Write ANSYS Input File andchoose to write the solution setup to the file .2.The mesh is automatically generated as part of this process. If you want to examine it,select Mesh from the tree.3.Save the Simulation database, use the tab near the top of the Workbench window to returnto the Oscillating Plate [Project] tab, and save the project itself.4.Setting up the Fluid Physics and ANSYS Multi-field Settings in ANSYS CFX-PreThis section describes the step-by-step definition of the flow physics and ANSYS Multi-field settings in ANSYS CFX-Pre.Playing a Session FileIf you want to skip past these instructions and to have ANSYS CFX-Pre set up the simulation automatically, you can select Session > Play Tutorial from the menu in ANSYS CFX-Pre, then run the session file: . After you have played the session file as described in earlier tutorials under Playing the Session File and Starting ANSYS CFX-Solver Manager, proceed to Obtaining a Solution using ANSYS CFX-Solver Manager.Creating a New Simulation1.Start ANSYS CFX-Pre.2.Select File > New Simulation.3.Select General and click OK.4.Select File > Save Simulation As.5.Under File name, type OscillatingPlate.6.Click Save.Importing the Mesh1.Right-click Mesh and select Import Mesh.2.Select the provided mesh file, and click Open.Note：The file that was just created in Simulation, , will be used as an input file for the ANSYS Solver.Setting the Simulation TypeA transient ANSYS Multi-field run executes as a series of timesteps. The Simulation Type tab is used both to enable an ANSYS Multi-field run and to specify the time-related settings for it (in the External Solver Coupling settings). The ANSYS input file is read by ANSYS CFX-Pre so that it knows which Fluid Solid Interfaces are available.Once the timesteps and time duration are specified for the ANSYS Multi-field run (coupling run), ANSYS CFX automatically picks up these settings and it is not possible to set the timestep and time duration independently. Hence the only option available for Time Duration is Coupling Time Duration, and similarly for the related settings Time Step and Initial Time.1.Click Simulation Type .2.Apply the following settingsTab Setting ValueBasic Settings External Solver Coupling > Option ANSYS MultiFieldExternal Solver Coupling > ANSYS Input File[]Coupling Time Control > Coupling Time Duration > TotalTime5 [s]Coupling Time Control > Coupling Time Steps > Option TimestepsCoupling Time Control > Coupling Time Steps > Timesteps [s]Simulation Type > Option TransientSimulation Type > Time Duration > Option Coupling Time Duration Simulation Type > Time Steps > Option Coupling Time Steps Simulation Type > Initial Time > Option Coupling Initial Time[] This file is located in your working directory.3.Click OK.Note：You may see a physics validation message related to the difference in the units used in ANSYS CFX-Pre and the units contained within the ANSYS input file. While it is important to review the units used in any simulation, you should be aware that, in this specific case, the message is not crucial as it is related to temperature units and there is no heat transfer in this case. Therefore, this specific tutorial will not be affected by the physics message.Creating the FluidA custom fluid is created with user-specified properties.1.Click Material .2.Set the name of the new material to Fluid.3.Apply the following settingsTab Setting ValueBasic Settings Option Pure Substance Thermodynamic State (Selected) Thermodynamic State > Thermodynamic State LiquidMaterial Properties Equation of State > Molar Mass 1 [kg kmol^-1]4.Click OK.Creating the DomainIn order to allow the ANSYS Solver to communicate mesh displacements to the CFX Solver, mesh motion must be activated in CFX.1.Right click Simulation in the Outline tree view and ensure that Automatic DefaultDomain is selected. A domain named Default Domain should now appear under the Simulation branch.2.Double click Default Domain and apply the following settings3.Click OK.Creating the Boundary ConditionsIn addition to the symmetry conditions, another type of boundary condition corresponding with the interaction between the solid and the fluid is required in this tutorial.Fluid Solid External BoundaryThe interface between ANSYS and CFX is defined as an external boundary in CFX that has its mesh displacement being defined by the ANSYS Multi-field coupling process.When an ANSYS Multi-field specification is being made in ANSYS CFX-Pre, it is necessary to provide the name and number of the matching Fluid Solid Interface that was created in Simulation. Since the interface number in Simulation was 1, the name in question is FSIN_1. (If the interface number had been 2, then the name would have been FSIN_2, and so on.)On this boundary, CFX will send ANSYS the forces on the interface, and ANSYS will send back the total mesh displacement it calculates given the forces passed from CFX and the other defined loads.1.Create a new boundary condition named Interface.2.Apply the following settings3.Click OK.Symmetry BoundariesSince a 2D representation of the flow field is being modeled (using a 3D mesh with one element thickness in the Z direction) symmetry boundaries will be created on the low and high Z 2D regions of the mesh.1.Create a new boundary condition named Sym1.2.Apply the following settings3.Click OK.4.Create a new boundary condition named Sym2.5.Apply the following settings6.Click OK.Setting Initial ValuesSince a transient simulation is being modeled, initial values are required for all variables.1.Click Global Initialization .2.Apply the following settings:Tab Setting ValueGlobal Settings Initial Conditions > Cartesian Velocity Components > U0 [m s^-1] Initial Conditions > Cartesian Velocity Components > V0 [m s^-1] Initial Conditions > Cartesian Velocity Components > W0 [m s^-1] Initial Conditions > Static Pressure > RelativePressure0 [Pa]3.Click OK.Setting Solver ControlVarious ANSYS Multi-field settings are contained under Solver Control under the External Coupling tab. Most of these settings do not need to be changed for this simulation.Within each timestep, a series of “coupling” or “stagger” iterations are performed to ensure that CFX, ANSYS and the data exchanged between the two solvers are all consistent. Within each stagger iteration, ANSYS and CFX both run once each, but which one runs first is a user-specifiable setting. In general, it is slightly more efficient to choose the solver that drives the simulation to run first. In this case, the simulation is being driven by the initial pressure applied in ANSYS, so ANSYS is set to solve before CFX within each stagger iteration.1.Click Solver Control .2.Apply the following settings:Tab Setting ValueBasic Settings Transient Scheme > OptionSecond OrderBackward Euler Convergence Control > Minimum Number ofCoefficient Loops(Selected) Convergence Control > Minimum Number ofCoefficient Loops > Min. Coeff. Loops2[]Convergence Control > Max. Coeff. Loops 3External Coupling Coupling Step Control > Solution SequenceControl > Solve ANSYS FieldsBefore CFX FieldsTab Setting Value [] This setting is optional. The default value of 1 is also acceptable.3.Click OK.Setting Output ControlThis step sets up transient results files to be written at set intervals.1.Click Output Control .2.On the Trn Results tab, create a new transient result with the default name.3.Apply the following settings to Transient Results 1:Setting ValueOption Selected VariablesOutput Variable List Pressure, Total Mesh Displacement, VelocityOutput Frequency > Option Every Coupling Step[][] This setting writes a transient results file every multi-field timestep.4.Click the Monitor tab.5.Select Monitor Options.6.Under Monitor Points and Expressions:7.Click Add new item and accept the default name.8.Set Option to Cartesian Coordinates.9.Set Output Variables List to Total Mesh Displacement X.10.Set Cartesian Coordinates to [0, 1, 0].11.Click OK.Writing the Solver (.def) File1.Click Write Solver File .2.If the Physics Validation Summary dialog box appears, click Yes to proceed.3.Apply the following settingsSetting ValueFile nameQuit CFX–Pre[](Selected)[] If using ANSYS CFX-Pre in Standalone Mode.4.Ensure Start Solver Manager is selected and click Save.5.If you are notified the file already exists, click Overwrite.6.This file is provided in the tutorial directory and will exist in your working folder if youhave copied it there.7.Quit ANSYS CFX-Pre, saving the simulation (.cfx) file at your discretion.5.Obtaining a Solution using ANSYS CFX-Solver ManagerThe execution of an ANSYS Multi-field simulation requires both the CFX and ANSYS solvers to be running and communicating with each other. ANSYS CFX-Solver Manager can be used to launch both solvers and to monitor the output from both.1.Ensure the Define Run dialog box is displayed.There is a new MultiField tab which contains settings specific for an ANSYS Multi-field simulation.2.On the MultiField tab, check that the ANSYS input file location is correct (the location isrecorded in the definition file but may need to be changed if you have moved files around).3.On UNIX systems, you may need to manually specify where the ANSYS installation is ifit is not in the default location. In this case, you must provide the path to the v110/ansys directory.4.Click Start Run.The run begins by some initial processing of the ANSYS Multi-field input which results in the creation of a file containing the necessary multi-field commands for ANSYS, and then the ANSYS Solver is started. The CFX Solver is then started in such a way that it knows how to communicate with the ANSYS Solver.After the run is under way, two new plots appear in ANSYS CFX-Solver Manager:ANSYS Field Solver (Structural) This plot is produced only when the solid physics is set to use large displacements or when other non-linear analyses are performed. It shows convergence of the ANSYS Solver. Full details of the quantities are described in the ANSYS user documentation. In general, the CRIT quantities are the convergence criteria for each relevant variable, and the L2 quantities represent the L2 Norm of the relevant variable. For convergence, the L2 Norm should be below the criteria. The x-axis of the plot is the cumulative iteration number for ANSYS, which does not correspond to either timesteps or stagger iterations. Several ANSYS iterations will beperformed for each timestep, depending on how quickly ANSYS converges. You will usually see a somewhat “spiky” plot, as each quantity will be unconverged at the start of each timestep, and then convergence will improve.ANSYS Interface Loads (Structural)This plot shows the convergence for each quantity that is part of the data exchanged between the CFX and ANSYS Solvers. In this case, four lines appear, corresponding to two force components (FX and FY) and two displacement components (UX and UY). Since the analysis is 2D, FZ and UZ are not exchanged. Each quantity is converged when the plot shows a negative value. The x-axis of the plot corresponds to the cumulative number of stagger iterations (coupling iterations) and there are several of these for every timestep. Again, a spiky plot is expected as the quantities will not be converged at the start of a timestep.The ANSYS out file is displayed in ANSYS CFX-Solver Manager as an extra tab. Similar to the CFX out file, this is a text file recording output from ANSYS as the solution progresses.1.Click the User Points tab and watch how the top of the plate displaces as the solutiondevelops.2.When the solvers have finished and ANSYS CFX-Solver Manager puts up a dialog boxto tell you this, click Yes to post-process the results.3.If using Standalone Mode, quit ANSYS CFX-Solver Manager.6.Viewing Results in ANSYS CFX-PostFor an ANSYS Multi-field run, both the CFX and ANSYS results files will be opened up in ANSYS CFX-Post by default if ANSYS CFX-Post is started from a finished run in ANSYS CFX-Solver Manager.Plotting Results on the SolidWhen ANSYS CFX-Post reads an ANSYS results file, all the ANSYS variables are available to plot on the solid, including stresses and strains. The mesh regions available for plots by default are limited to the full boundary of the solid, plus certain named regions which are automatically created when particular types of load are added in Simulation. For example, any Fluid Solid Interface will have a corresponding mesh region with a name such as FSIN 1. In this case, there is also a named region corresponding to the location of the fixed support, but in general pressure loads do not result in a named region.You can add extra mesh regions for plotting by creating named selections in Simulation - see the Simulation product documentation for more details. Note that the named selection must have a name which contains only English letters, numbers and underscores for the named mesh region to be successfully created.Note that when ANSYS CFX-Post loads an ANSYS results file, the true global range for each variable is not automatically calculated, as this would add a substantial amount of time onto how long it takes to load such a file (you can turn on this calculation using Edit > Options and using the Pre-calculate variable global ranges setting under CFX-Post> Files). When the global range is first used for plotting a variable, it is calculated as the range within the current timestep. As subsequent timesteps are loaded into ANSYS CFX-Post, the Global Range is extended each time variable values are found outside the previous Global Range.1.Turn on the visibility of Boundary ANSYS (under ANSYS > Domain ANSYS).2.Right-click a blank area in the viewer and select Predefined Camera > View Towards-Z. Zoom into the plate to see it clearly.3.Apply the following settings to Boundary ANSYS:4.Click Apply.5.Select Tools> Timestep Selector from the task bar to open the Timestep Selectordialog box. Notice that a separate list of timesteps is available for each results file loaded, although for this case the lists are the same. By default, Sync Cases is set to By Time Value which means that each time you change the timestep for one results file, ANSYS CFX-Post will automatically load the results corresponding to the same time value for all other results files.6.Set Match to Nearest Available.7.Change to a time value of 1 [s] and click Apply.The corresponding transient results are loaded and you can see the mesh move in both the CFX and ANSYS regions.1.Clear the visibility check box of Boundary ANSYS.2.Create a contour plot, set Locations to Boundary ANSYS and Sym2, and set Variable toTotal Mesh Displacement. Click Apply.ing the timestep selector, load time value [s] (which is where the maximum totalmesh displacement occurs).This verifies that the contours of Total Mesh Displacement are continuous through both the ANSYS and CFX regions.Many FSI cases will have only relatively small mesh displacements, which can make visualization of the mesh displacement difficult. ANSYS CFX-Post allows you to visually magnify the mesh deformation for ease of viewing such displacements. Although it is not strictly necessary for this case, which has mesh displacements which are easily visible unmagnified, this is illustrated by the next few instructions.ing the timestep selector, load time value [s] (which has a much smaller meshdisplacement than the currently loaded timestep).2.Place the mouse over somewhere in the viewer where the background color is showing.Right-click and select Deformation > Auto. Notice that the mesh displacements are now exaggerated. The Auto setting is calculated to make the largest mesh displacement a fixed percentage of the domain size.3.To return the deformations to their true scale, right-click and select Deformation > TrueScale.Creating an Animationing the Timestep Selector dialog box, ensure the time value of [s] is loaded.2.Clear the visibility check box of Contour 1.3.Turn on the visibility of Sym2.4.Apply the following settings to Sym2.5.Click Apply.6.Create a vector plot, set Locations to Sym1 and leave Variable set to Velocity. SetColor to be Constant and choose black. Click Apply.7.Select the visibility check box of Boundary ANSYS, and set Color to a constant blue.8.Click Animation .The Animation dialog box appears.9.Select Keyframe Animation.10.In the Animation dialog box:a.Click New to create KeyframeNo1.b.Highlight KeyframeNo1, then change # of Frames to 48.c.Load the last timestep (50) using the timestep selector.d.Click New to create KeyframeNo2.The # of Frames parameter has no effect for the last keyframe, so leave it at thedefault value.e.Select Save MPEG.f.Click Browse next to the MPEG file data box to set a path and file name forthe MPEG file.If the file path is not given, the file will be saved in the directory from whichANSYS CFX-Post was launched.g.Click Save.The MPEG file name (including path) will be set, but the MPEG will not becreated yet.h.Frame 1 is not loaded (The loaded frame is shown in the middle of theAnimation dialog box, beside F:). Click To Beginning to load it then waita few seconds for the frame to load.i.Click Play the animation .The MPEG will be created as the animation proceeds. This will be slow, since atimestep must be loaded and objects must be created for each frame. To view theMPEG file, you need to use a viewer that supports the MPEG format.11.When you have finished, exit ANSYS CFX-Post.。
ANSYS流固耦合
教程大纲
在这个教程中您将学到：
– – – – 移动网格 流体－固体相互作用模拟 运用ANSYS-MultiField模拟 同时处理两个结果文件
问题概述
在这个教程中，运用一个简单的摆动板例题来解释 怎样建立以及模拟流体－结构相互作用的问题。其 中流体模拟在ANSYS CFX求解器中运行，而用 ANSYS软件包中的FEA来模拟固体问题。模拟流固 相互作用的整个过程中需要两个求解器的耦合运 行，ANSYS－MultiField求解器提供了耦合求解的平 台。
4. 点击OK
设置流体问题、 中设置ANSYS MultiField 设置流体问题、在ANSYS CFX-Pre中设置 中设置
创建域：为了使ANSYS Solver能够把网格变形信息传递给 CFX Solver，在CFX中必须激活网格移动。 1. 重命名Default Domain为OscillatingPlate，并打开进行编 辑 2. 应用以下设置
8.
点击OK
设置流体问题、 中设置ANSYS MultiField 设置流体问题、在ANSYS CFX-Pre中设置 中设置
输出求解器文件(.def) 1. 点击Write Solver File 2. 如果 Physics Validation Summary 对话框出现，点击 Yes 以继续 3. 应用以下设置
3.
点击OK
设置流体问题、 中设置ANSYS MultiField 设置流体问题、在ANSYS CFX-Pre中设置 中设置
创建边界条件 • 流体外部边界
1. 2. 创建一个新边界条件，命名为Interface. 应用以下设置
3.
点击OK
设置流体问题、 中设置ANSYS MultiField 设置流体问题、在ANSYS CFX-Pre中设置 中设置
ANSYS Workbench LS-DYNA流固耦合方法应用
ANSYS Workbench LS-DYNA流固耦合方法应用贮液容器（含塑料瓶）广泛应用于化工、食品包装、储运等领域。
由于容器（含塑料瓶）在运输和使用过程中常常会因为跌落或碰撞冲击导致破损而造成损失和污染，因此，研究贮液容器（含塑料瓶）在跌落碰撞过程中的力学行为，对认识容器（含塑料瓶）跌落碰撞损伤机理，优化容器（含塑料瓶）结构，提高其安全性和使用价值意义重大。
．贮液容器的跌落是一个典型的流固耦合问题，可采用LS-DYNA的ALE算法（任意拉格朗日欧拉算法）进行模拟。
下面以一个封闭的装水水箱为例，介绍ANSYS Workbench LS-DYNA分析此类型跌落问题的方法和步骤：1.建立几何模型调用ANSYS Workbench中的LS-DYNA模块，如图1所示。
然后使用ANSYS的CAD工具DesignModeler建立几何模型，如图2所示。
图1 调用Workbench LS-DYNA 图2 DesignModeler中建立几何模型2.生成K文件双击进入“Model”后，对模型进行网格划分、边界条件设置、速度设置和分析设置，如图3所示。
设置完成后点击“solve”求解，生成K文件，如图4所示。
图3 调用Workbench LS-DYNA 图4 DesignModeler中建立几何模型3.编辑K文件通过Workbench LS-DYNA生成的K文件中关键字是不够完善的，并不能直接递交LS-DYNA求解器进行求解。
K文件中所欠缺的一些关键字，在流固耦合分析中是必不可少的，如空材料的定义、跟随坐标系的定义、空白域的定义以及状态方程的定义等。
3.1 重要关键字释义（1）LS-DYNA程序提供了运动的多物质ALE网格，可以方便地为多物质ALE算法定义跟随坐标系*ALE_REFERENCE_SYSTEM_NODE*ALE_REFERENCE_SYSTEM_GROUP（2）定义空材料和状态方程的关键字*MAT_NULL *EOS（3）初始化空白域的关键字*INITIAL_VOID_PART（4）结构和流体之间耦合的关键字*CONSTRAINED_LAGRANGE_IN_SOLID（5）单元算法定义（单点积分的单物质加空白材料）的关键字*SECTION_SOLID_ALE ELF0RM=12（6）在重力作用下产生下落的关键字*LOAD_BODY……3.2关键字编辑方法关键字的编辑或修改一般有两种方法，一种是直接在ls-prepost中对关键字进行编辑设置，如图5所示；另一种是在文本编辑器UltraEdit中对关键字进行编辑或修改，如图6所示。
ansys流固耦合案例
ansys流固耦合案例1. Ansys流固耦合案例：热沉设计热沉是一种用于散热的设备，通常用于电子设备中，以降低温度并保护设备不受过热损坏。
在设计热沉时，流体流动和热传导是两个重要的物理过程。
Ansys流固耦合可以帮助工程师模拟和优化热沉的设计。
在这个案例中，我们考虑了一个由铝合金制成的热沉。
热沉的底部与电子设备紧密接触，通过流体流动和热传导来吸收和传递热量。
通过使用Ansys的流固耦合模块，我们可以解决以下问题：1) 流体流动模拟：我们可以使用Ansys Fluent模块模拟流体在热沉内部的流动情况。
通过设定合适的边界条件和材料属性，我们可以计算出流体的速度场和压力场。
2) 热传导模拟：我们可以使用Ansys Mechanical模块模拟热沉内部的热传导过程。
通过设定热源和材料属性，我们可以计算出热沉内部的温度分布。
3) 流固耦合模拟：在流体流动和热传导模拟的基础上，我们可以使用Ansys的流固耦合模块将二者结合起来。
通过设定合适的耦合条件，我们可以模拟出流体对热沉的冷却效果，并计算出热沉的最终温度分布。
通过这个案例，我们可以优化热沉的设计，以达到更好的散热效果。
我们可以调整热沉的几何形状、材料属性和流体流动条件，以最大程度地提高散热效率，并确保电子设备的正常运行。
2. Ansys流固耦合案例：风力发电机叶片设计风力发电机叶片是将风能转化为机械能的关键部件。
在设计风力发电机叶片时，流体力学和结构力学是两个重要的物理过程。
Ansys 流固耦合可以帮助工程师模拟和优化叶片的设计。
在这个案例中，我们考虑了一个三叶式风力发电机叶片。
叶片由复合材料制成，通过受风力作用，将机械能传递给发电机。
通过使用Ansys的流固耦合模块，我们可以解决以下问题：1) 风场模拟：我们可以使用Ansys Fluent模块模拟风力对叶片的作用。
通过设定合适的边界条件和材料属性，我们可以计算出风场的速度场和压力场。
2) 结构分析：我们可以使用Ansys Mechanical模块模拟叶片的结构响应。
ansys流固耦合模态分析
有问题可以发邮件给我一起讨论**************FSI流固耦合命令求解流固耦合问题使用ANSYS计算结构在水中的模态时, FLUID29,FLUID30单元分别用来模拟二维和三维流体部分,相应的结构模型则利用PLANE42单元和SOL ID45等单元来构造，其中，PLANE42和SOL ID45分别是用来构造二维和三维结构模型的单元。
FLUID30是流体声单元,主要用于模拟流体介质及流固耦合问题。
该单元有8 个节点,每个节点上有4 个自由度,分别是XYZ上3个方向位移自由度和1个压力自由度,为各向同性材料。
输入材料属性时,需要输入流体的材料密度(作为DENS 输入)及流体声速(作为SONC输入),流体粘性产生的损耗效应忽略不计。
FLUID29是FLUID30单元在二维上的简化，少了一个Z向的位移。
SOLID45单元用于构造三维实体结构。
单元通过8 个节点来定义,每个节点有3 个沿着XYZ方向平移的自由度。
PLANE42是SOLID45单元在二维上的简化。
在利用ANSYS建模分析时,流场域单元属性分为2种,由KEYOPT(2)(指定流体和结构分界面处结构是否存在) 控制,在流固耦合交界面上的单元KEYOPT(2) = 0 ,表示分界面处有结构,其他流体单元KEYOPT(2)=1,表示分界面处无结构。
流体-结构分界面通过面载荷标志出来,指定FSI label可以把分界面处的结构运动和流体压力耦合起来,分界面标志在分界面处的流体单元标出。
数值分析的步骤1) 建立流体单元的实体模型。
建立流体模型,需要确定流体域的范围,可以把无限边界流体简化成流体区域的半径为固体结构半径的10倍。
2) 标记流固耦合界面。
选取流体单元中流固交界面上的节点,执行FSI 命令,流固耦合交界面的处理:流体与固体是两个独立的实体,在划分单元时在两者交界面上的单元网格要划分一致,这样在交界面上的同一位置一般就有两个重合的节点,一个节点属于流体单元,一个节点属于固体单元,这两个重合节点在交界面的位移强制保持一致。
ansys流固耦合案例
ansys流固耦合案例流固耦合是指流体和固体之间相互作用的一种现象，也是工程实际中经常遇到的一种情况。
在ANSYS软件中，可以通过流固耦合分析来模拟和研究这种相互作用。
下面列举了10个符合要求的ANSYS 流固耦合案例。
1. 水流对桥梁的冲击分析：通过ANSYS流固耦合分析，研究水流对桥梁结构的冲击力和应力分布情况，以评估桥梁的稳定性。
2. 水下管道的流固耦合分析：通过ANSYS软件中的流固耦合模块，模拟水下管道在水流作用下的应力和变形情况，以确定管道的安全性能。
3. 水泵的流固耦合分析：利用ANSYS软件中的流固耦合模块，模拟水泵在工作状态下的流体流动和叶轮的应力分布，以优化水泵的设计。
4. 风力发电机叶片的流固耦合分析：通过ANSYS流固耦合分析，研究风力发电机叶片在风力作用下的变形和应力分布情况，以提高叶片的性能和可靠性。
5. 汽车底盘的流固耦合分析：利用ANSYS软件中的流固耦合模块，模拟汽车底盘在行驶过程中的气动力和振动响应，以改善车辆的稳定性和乘坐舒适性。
6. 船舶结构的流固耦合分析：通过ANSYS流固耦合分析，研究船舶结构在船体运动和海洋波浪作用下的应力和变形情况，以提高船舶的稳定性和安全性。
7. 石油钻井过程中的流固耦合分析：利用ANSYS软件中的流固耦合模块，模拟石油钻井过程中的井筒流体流动和井壁的应力分布，以优化钻井工艺和提高钻井效率。
8. 液压缸的流固耦合分析：通过ANSYS流固耦合分析，研究液压缸在工作过程中的液体流动和缸体的应力分布情况，以提高液压缸的性能和可靠性。
9. 燃烧室的流固耦合分析：利用ANSYS软件中的流固耦合模块，模拟燃烧室内燃烧过程中的流体流动和壁面的热应力分布，以改善燃烧室的燃烧效率和寿命。
10. 水轮机的流固耦合分析：通过ANSYS流固耦合分析，研究水轮机叶片在水流作用下的变形和应力分布情况，以提高水轮机的转换效率和可靠性。
以上是符合要求的10个ANSYS流固耦合分析案例，这些案例涵盖了不同领域和不同类型的流固耦合问题，可以帮助工程师和设计师更好地理解和解决实际工程中的流固耦合问题。
ANSYS Workbench LS-DYNA流固耦合方法应用
ANSYS Workbench LS-DYNA流固耦合方法应用贮液容器（含塑料瓶）广泛应用于化工、食品包装、储运等领域。
由于容器（含塑料瓶）在运输和使用过程中常常会因为跌落或碰撞冲击导致破损而造成损失和污染，因此，研究贮液容器（含塑料瓶）在跌落碰撞过程中的力学行为，对认识容器（含塑料瓶）跌落碰撞损伤机理，优化容器（含塑料瓶）结构，提高其安全性和使用价值意义重大。
．贮液容器的跌落是一个典型的流固耦合问题，可采用LS-DYNA的ALE算法（任意拉格朗日欧拉算法）进行模拟。
下面以一个封闭的装水水箱为例，介绍ANSYS Workbench LS-DYNA 分析此类型跌落问题的方法和步骤：1.建立几何模型调用ANSYS Workbench中的LS-DYNA模块，如图1所示。
然后使用ANSYS的CAD工具DesignModeler建立几何模型，如图2所示。
图1 调用Workbench LS-DYNA图2 DesignModeler中建立几何模型2.生成K文件双击进入“Model”后，对模型进行网格划分、边界条件设置、速度设置和分析设置，如图3所示。
设置完成后点击“solve”求解，生成K文件，如图4所示。
图3调用Workbench LS-DYNA图4DesignModeler中建立几何模型3.编辑K文件通过Workbench LS-DYNA生成的K文件中关键字是不够完善的，并不能直接递交LS-DYNA求解器进行求解。
K文件中所欠缺的一些关键字，在流固耦合分析中是必不可少的，如空材料的定义、跟随坐标系的定义、空白域的定义以及状态方程的定义等。
3.1重要关键字释义（1）LS-DYNA程序提供了运动的多物质ALE网格，可以方便地为多物质ALE算法定义跟随坐标系*ALE_REFERENCE_SYSTEM_NODE*ALE_REFERENCE_SYSTEM_GROUP（2）定义空材料和状态方程的关键字*MAT_NULL*EOS（3）初始化空白域的关键字*INITIAL_VOID_PART（4）结构和流体之间耦合的关键字*CONSTRAINED_LAGRANGE_IN_SOLID（5）单元算法定义（单点积分的单物质加空白材料）的关键字*SECTION_SOLID_ALE ELF0RM=12（6）在重力作用下产生下落的关键字*LOAD_BODY……3.2关键字编辑方法关键字的编辑或修改一般有两种方法，一种是直接在ls-prepost中对关键字进行编辑设置，如图5所示；另一种是在文本编辑器UltraEdit中对关键字进行编辑或修改，如图6所示。
ANSYS流固耦合分析实例
为0 [s]设置压力为100 [pa] 5. 表中需要继续输入两排参数，100 [pa]对应于0.499 [s]， 0 [pa]
对应于0.5 [s]
模拟中固体问题的描述—记录ANSYS输入文件
现在，模拟设置已经完成。在Simulation中ANSYS MultiField 并不运行，因此用求解器按钮并不能得到结果 1. 然 而 ， 在 目 录 树 中 的 高 亮 Solution 中 ， 选 择 Tools > Write ANSYS Input File，把结果写进文件OscillatingPlate.inp 2. 网格是自动生成的，如果想检查，可以在目录树中选择Mesh 3. 保存Simulation数据，返回Oscillating Plate [Project]面板， 存储Project
固定支撑：为确保薄板的底部固定于平板，需要设置固定支撑 条件。
1. 右击目录树中Transient Stress，在快捷菜单中选择Insert > Fixed Support
2. 用旋转键 旋转几何模型，以便可以看见模型底面（low-y）， 然后选择 并点击底面（low-y）
3. 在Details窗口，选择Geometry，然后点击No Selection使Apply 按钮出现（如果需要）。点击Apply以设置固支。
设置仿真类型： 1. 选择 Insert > Simulation Type. 2. 应用以下设置： 3. 点击OK
设置流体问题、在ANSYS CFX-Pre中设置ANSYS MultiField
建立流体物质 1. 选择 Insert > Material. 2. 把新物质名定义为 Fluid. 3. 应用以下设置
ansys流固耦合案例
ansys流固耦合案例
ANSYS流固耦合是一种模拟分析技术，用于研究流体和固体之间的相互作用。
它可以在一个模拟中同时考虑流体和固体的运动和变形，从而更准确地预测系统的行为。
以下是一些ANSYS流固耦合的应用案例：
1. 水下爆炸冲击分析：在这种情况下，流固耦合分析可以用于研究水中的爆炸冲击对周围结构的影响。
通过考虑水的流动和固体结构的变形，可以更准确地预测爆炸冲击的传播路径和结构的破坏程度。
2. 风力发电机叶片设计：在风力发电机中，叶片的设计对其性能至关重要。
流固耦合分析可以用于优化叶片的形状和材料，以最大限度地提高能量转换效率。
通过考虑风的流动和叶片的变形，可以预测叶片的受力情况和振动特性。
3. 水力润滑轴承分析：在水力润滑轴承中，流体的流动对轴承的性能和寿命有重要影响。
流固耦合分析可以用于优化轴承的设计，以减少摩擦和磨损，并提高轴承的承载能力。
通过考虑流体的流动和轴承的变形，可以预测轴承的润滑性能和寿命。
4. 波浪对海洋结构物的影响分析：在海洋工程中，波浪对海洋结构物的影响是一个重要的研究领域。
流固耦合分析可以用于研究波浪对海洋平台、堤岸和海底管道等结构物的冲击和振动情况。
通过考虑波浪的流动和结构物的变形，可以预测结构物的破坏程度和安全
性能。
这些案例只是流固耦合分析的一小部分应用领域，实际上在工程和科学研究中有很多其他的应用。
ANSYS作为一种强大的模拟软件，可以帮助工程师和科学家更好地理解和优化流体和固体系统的相互作用。
ansys流固耦合分析与工程实例
第 1 章 流固耦合分析基础近年来，流固耦合分析研究和应用取得了飞速的发展，尤其是 ANSYS Workbench 推广以 来，流固耦合分析变得容易起来，也因此很快在相关工程领域得到广泛应用。
本章是学习 ANSYS 流固耦合分析的入门篇，旨在介绍 ANSYS 流固耦合分析的基本知识，引导初学者由 浅入深地了解流固耦合分析的基本操作和应用。
本章内容包括：ü 流固耦合基础ü ANSYS 流固耦合分析ü ANSYS 流固耦合分析的基本步骤1.1 流固耦合基础下面简单介绍什么是流固耦合作用、流固耦合分析，流固耦合的重要性，以及流固耦合分 析用到的控制方程。
1.1.1 认识流固耦合分析的重要性随着计算科学以及数值分析方法的不断发展， 流固耦合或交互作用 （fluid structure coupling 或 fluid structure interaction ）研究从 20 世纪 80年代以来，受到了世界学术界和工业界的广泛 关注。
流固耦合问题是流体力学（Computational Fluid Dynamics ，CFD ）与固体力学 （Computational Solid Mechanics ，CSM ）交叉而生成的一门力学分支，同时也是多学科或多 物理场研究的一个重要分支， 它是研究可变形固体在流场作用下的各种行为以及固体变形对流 场影响这二者相互作用的一门科学。
流固耦合问题可以理解为既涉及固体求解又涉及流体求解， 而两者又都不能被忽略的模拟 问题。
因为同时考虑流体和结构特性，流固耦合可以有效节约分析时间和成本，同时保证结果 更接近于物理现象本身的规律。
所以， 近年来流固耦合分析在工程设计特别是虚拟设计和仿真 中的应用越来越广泛和深入。
1流固耦合分析基础ANSYS 流固耦合分析与工程实例2 图 11 显示了流固耦合分析在产品虚拟设计中的层次以及与各学科之间的相互联系。
【达尔整理】ANSYS流固耦合分析实例命令流
达尔文档DareDoc分享知识传播快乐ANSYS流固耦合分析实例命令流本资料来源于网络，仅供学习交流2015年10月达尔文档|DareDoc整理目录ANSYS流固耦合例子命令流............................................................................. 错误!未定义书签。
ANSYS流固耦合的方式 (3)一个流固耦合模态分析的例子1 (3)一个流固耦合模态分析的例子2 (4)一个流固耦合建模的例子 (7)一加筋板在水中的模态分析 (8)一圆环在水中的模态分析 (10)接触分析实例---包含初始间隙 (14)耦合小程序 (19)流固耦合练习 (21)一个流固耦合的例子 (22)使用物理环境法进行流固耦合的实例及讲解 (23)针对液面晃动问题，ANSYS/LS-DYNA提供三种方法 (30)1、流固耦合 (30)2、SPH算法 (34)3、ALE（接触算法） (38)脱硫塔于浆液耦合的分析 (42)ANSYS坝-库水流固耦合自振特性的例子 (47)空库时的INP文件 (47)满库时的INP文件 (49)计算结果 (52)ANSYS流固耦合的方式一般说来，ANSYS的流固耦合主要有4种方式：1，sequential这需要用户进行APDL编程进行流固耦合sequentia指的是顺序耦合以采用MpCCI为例,你可以利用ANSYS和一个第三方CFD产品执行流固耦合分析。
在这个方法中，基于网格的平行代码耦合界面(MpCCI) 将ANSYS和CFD程序耦合起来。
即使网格上存在差别，MpCCI也能够实现流固界面的数据转换。
ANSYS CD中包含有MpCCI库和一个相关实例。
关于该方法的详细信息，参见ANSYS Coupled-Field Analysis Guide中的Sequential Couplin2，FSI solver流固耦合的设置过程非常简单，推荐你使用这种方式3，multi-field solver这是FSI solver的扩展，你可以使用它实现流体，结构，热，电磁等的耦合4，直接采用特殊的单元进行直接耦合，耦合计算直接发生在单元刚度矩阵一个流固耦合模态分析的例子1这是一个流固耦合模态分析的典型事例，采用ANSYS/MECHANICAL可以完成。
ansys workbench的管道热流固耦合案例
图 3 fill 命令选取内部面
图 4 入口出口命名
选定所有外部壁面定义为 wall。最后定义耦合面，定义流固交界面流体一侧的三个面为 interfacef2s，定义流固交界面固体一侧的三个面为 interfaces2f，面的选取如图 5 所示。
图 5 流体域和固体域边界图示
四、网格划分
双击 A3 打开 Meshing 模块，网格划分主要有三部分，选定固体域定义网格方法为 Automatic Method，选定流体域定义网格方法同样为 Automatic Method，最后，在流体域中 选择与固体域相交的三个面定义膨胀层 Inflation。为了使网格更合适质量更好，在 detail of ‘mesh’面板中定义相应参数，其中定义 Relevance 为 100，Relevance Center 为 fine，Smoothing 为 High，Span Angle Center 为 Fine，其余选项均保持默认即可。单击 Generate Mesh 生成网 格，得到节点数为 64628，网格数量为 190857。观察网格质量，网格质量总体均在 0.5 以上， 基本可以认为网格质量良好。
七、变形及热应力分析
双击 C5 进入静态结构计算模块右键单击 Imported Load 打开右键菜单后单击 Imported Load 导入固体域的温度。右键单击 Static Structural—Insert—Fixed Support 给三个入口端面
施加固定约束。完成边界条件的加载。右键单击 Solution 插入总变形和应力。单击 solve 进 行求解。
图 2 数据传送关系
在 SolidWorks 中 建 立 相 应 模 型 ， 并 转 化 成 ansys 适 用 的 x_t 格 式 。 双 击 A2 打 开 DesignModeler，导入相应模型。
ansys 小球跌落的流固耦合
ansys 小球跌落的流固耦合ANSYS是一种流体和固体力学仿真软件，可用于模拟各种流固耦合问题。
在此，我们将探讨小球跌落的流固耦合模拟。
小球跌落是一个经典的物理实验，它可以用于研究物体的运动学和动力学特性。
在这个实验中，我们将一个小球从一定高度自由落下，并观察其在空气中的运动状态。
由于空气的存在，小球受到了空气阻力的影响，这将影响小球的运动。
因此，我们需要进行流固耦合模拟来研究小球的运动状态。
在ANSYS中，我们可以使用FLUENT模块来模拟空气流动。
首先，我们需要创建一个三维模型，包括小球和周围的空气。
然后，我们需要定义空气的物理特性，如密度、粘度和温度等。
接下来，我们需要定义边界条件，如入口速度和出口压力等。
最后，我们可以运行模拟并观察空气流动的结果。
接下来，我们需要使用ANSYS中的Mechanical模块来模拟小球的运动。
我们需要将小球的模型导入Mechanical中，并定义其物理特性，如材料、密度和弹性模量等。
然后，我们需要定义边界条件，如重力和接触条件等。
最后，我们可以运行模拟并观察小球的运动状态。
在进行流固耦合模拟时，我们需要将FLUENT和Mechanical模块进行耦合。
这可以通过ANSYS Workbench中的Multi-FieldSolver实现。
在Multi-Field Solver中，我们需要定义FLUENT和Mechanical之间的耦合条件，如流体力和固体位移等。
然后，我们可以运行模拟并观察小球在空气中的运动状态，以及其与周围空气的相互作用。
在模拟小球跌落的流固耦合问题时，我们需要考虑以下因素：1.空气阻力：空气阻力将影响小球的运动状态，因此我们需要对空气流动进行准确的模拟。
2.重力：重力是小球运动的驱动力，我们需要准确地定义重力的作用。
3.接触：小球与地面的接触将影响其运动状态，因此我们需要准确地定义接触条件。
4.材料特性：小球的材料特性将影响其弹性和变形，我们需要准确地定义材料特性。
ANSYS流固耦合分析实例
选择 value 值为1.1 [s] 2. 置鼠标于浏览器中背景颜色显示的
地方，右击，选择Deformation > Auto 3. 为真实的反映变形，右击， 选择 Deformation >True Scale
通过 ANSYS CFX-Post 观察结果
5. 点击 Monitor 键 6. 选择Monitor Options
设置流体问题、在ANSYS CFX-Pre中设置ANSYS MultiField
7. 在Monitor Points and Expressions下 a. 点击Add new item ，采用默认的名字
b. 设置 Option 为 Cartesian Coordinates c. 设置 Output Variables List 为Total Mesh Displacement X d. 设置Cartesian Coordinates为[0, 1, 0]
Geometry File下，点击Browse，打开所提供 的OscillatingPlate.agdb文件 7. 确认OscillatingPlate.agdb被选（高亮显示）， 点击New simulation
模拟中固体问题的描述
建立固体材料 1. 当模拟界面展开，在模拟界面左边的目录树中展开
3. 点击OK
设置流体问题、在ANSYS CFX-Pre中设置ANSYS MultiField
创建边界条件 • 流体外部边界
1. 创建一个新边界条件，命名为Interface. 2. 应用以下设置
3. 点击OK
设置流体问题、在ANSYS CFX-Pre中设置ANSYS MultiField
ansys help流固耦合算例fluid_structure(内含解析)
*SET,rext , 6 ! Size ratio in flow direction of outlet
*SET,rafls , 12 ! Initial element spacing ratio - morph.fluid
lesize,9,,,nflu,raflu
lesize,15,,,nflu,raflu
lesize,18,,,nenty,1./raent
lesize,17,,,nenty,1./raent
lesize,21,,,nfl1,rafls
lesize,8,,,nfl11,-1./(rafls+3)
lesize,1,,,ngas,rgas !指定所选线上单元数 线1上划分10个单元 中间尺寸比两端尺寸=|-2|
lesize,3,,,ngas,rgas !指定所选线上单元数 线3上划分10个单元 中间尺寸比两端尺寸=|-2|
*SET,nfl11, nfl1*2+9
!! Morphing Fluid region is a user defined region around
!! the gasket. The fluid mesh here will deform and be
!! updated as the gasket deforms.
alls
!-----------------
!!
!!!!! 2. Create Physics Environment for the Fluid..................................................第二大步创建流体的物理环境
ansys应用-流固耦合
1. 打开 AWB，由于要做 FSI 双向流固耦合，所以先在框架中建立瞬态结构场， 如图 3 所示：（如果是单向流固耦合，可以直接使用 FSI 模块，丌过里面的结 构场是稳态结构场）
图3 2. 在 setup 处单击鼠标右键，弹出如图 4 的对话框，本例中按照图 2 选择，添
加流体计算的 CFX 部分：
1、Design Simulation 中定义好结构分析中的材料、网格、约束及流体边界。 2、写出 INP 格式的 ANSYS 结构文件。 3、CFX 中在 Simulation Type 中设置好 External Solver Coupling 为 ANSYS MultiField，并将第 2 步中写出的 INP 格式的 ANSYS 结构文件选中设为 ANSYS 文件。
图1 b.利用 ANSYS 中的 Read input from 命令读入结果载荷。
二 、 实 现 双 向 流 固 耦 合 的 方 法 主 要 有 三 种 ： CFX+Design Simulation(AWB) 、 CFX+ANSYS Classic 和 MFX+ANSYS Classic+CFX。 （1）、CFX+Design Simulation(AWB)方法流程：
（2）、CFX+ANSYS Classic 方法流程：
1、ANSYS Classic 中定义好结构分析中的材料、网格、约束及流体边界。 2、设置好 MFX 中的不 CFX 相联的系列条件，如载荷时间步及求解类型和步数 等等。 3、在 MFX 下的利用 write input 写出 ANSYS 的流固耦合文件（dat 格式）。 4、同方式一中的第 3 步，丌同就是将 CFX 中联结的 ANSYS 文件转为第 3 步写 出的 DAT 文件。 5、同方式一中的 4 至 6 步。注意的是 CFX 中的单位要不 ANSYS Classic 默认 的单位保持一致，ANSYS 不 CFX 中默认的耦合条件基本一样，只是在 CFX 中 默认为先求解 CFX，而 ANSYS 中默认为先求解 ANSYS，所以此处要注意保持 一致。
ANSYS 声学计算算例 流固耦合
ANSYS 声学计算算例水下圆柱壳体的建模与声学分析使用有限元软件ANSYS进行计算和分析时水下环肋圆柱壳体有限元模型的建立及结构声学分析主要分为以下一些步骤：1.建立壳体的实体模型（包括有圆柱壳体的建立，给圆柱壳体加环肋）；2.圆柱壳体外部流体介质的生成；3.对圆柱壳体和流体介质进行有限元4.设置流固耦合单元，并设置外部声场边界条件；5.在求解器中进行振动模态求解和受激励的谐响应求6.求解结果进行后处理分析。
，1.建立壳体的实体模型这个步骤主要是在预处理模块（PREP7）中完成首先是根据要建立的实体模型，进行单元的选取和定义这些单元的物理属性，水下圆柱壳体半径与壳体壁厚的比超过了20，根据ANSYS中单元的使用原则可以选用Shell63号薄壳单元，这种单元的有限元计算原理在前面已经介绍；环肋选用梁单元，ANSYS 提供了多种梁单元的结构形式，其中Beam188号梁单元符合作为壳体加强筋及肋骨的使用，所以在水下圆柱壳体环肋选用T的Beam188号梁单元进行建模；而流体介质根据分析中用途的不同要定义两种，一种是流体介质中的单元Fluid30号流体介质单元，一种是流体与结构接触的流固耦合面的单元选用Fluid30号流固耦合单元，在实际建模操作中还需要定义一种用于平面声场的29号单元（在计算中未用到，但在建模中需使用）；共需要定义五种单元。
Shell63壳体单元与Beam188梁单元为同一种材料，所以物理属性相同。
而Fluid30流体介质单元与Fluid30流固耦合单元物理属性也相同，及在分析中只需要定义两个物理属性即可。
具体的使用APDL命令定义为：/prep7 ！进行预处理模块et，1，30，！定义1号单元为Fluid30 流固耦合单元et，2，29 ！定义2号单元为Fluid29平面流体单元et，3，30 ，，1 ！定义3号单元为Fluid30流体介质单元et，4，63 ！定义4号单元为Shell63壳体单元et，5，188 ！定义5号单元为Beam188梁单元r，4，0.002 ！定义4号单元的厚度为2㎝mp，dens，4，7800 ！定义4号物理属性包括有密度mp，ex，4，2.1e11 !杨氏模量、mp，nuxy，4，0.3 ！泊松比mp，sonc，1，1460 ！设置水中声速mp，dens，1，1000 ！设置流体密度sectype，1，beam，T，! 选取T型梁secoffset,，orig ！设置梁的方向secdata，0.04，0.05，0.002，0.02，0，0，0，0，0，0 、所建立的圆柱壳体的参数：圆柱长为50 ㎝，半径为25 ㎝，壳体的壁厚为2 ㎝，cyl4，0，0，0.25，，5 ！形成圆面k，9，0，0，0 ! 定义原点k，10，0，0，0.5lstr，9，10 ！通过原点作直线adrag，5，6，7，8，，，9 ！通过放样形成圆柱wpoff，0，0，0.1asel，s，，，2，5asbw，all，，，！移动工作平面与选取的侧面相切…… ！重复上面操作，形成四个环肋面wpoff，0，0，-0.4 ！工作平面回到原点位置上k，31，0.2，0，0.1 ！定义环肋的方向点lsel，s，，，20 ！选择要划分为环肋的线段latt，4，5，5，，31，40，1 ！定义线段物理属性lesize，20，，，6 ！划分数目secnum，1lmesh，20 ！划分线段将上述的操作完成以后，壳体的模型基本完成,具体结构如图示图2-6 环肋圆柱壳体模型图2.圆柱壳体外部流体圆柱壳体外部的流体介质主要通过设置好的平面流体单元沿指定的线段进行放样，形成立体的流体介质单元。