fluent 二维大涡模拟命令

fluent二维大涡模拟命令

fluent二维大涡模拟命令Fluent是流体动力学模拟软件的一种，它提供了二维大涡模拟命令用于模拟二维涡旋动力学过程。

本文将分步骤阐述如何使用Fluent二维大涡模拟命令。

第一步，打开Fluent软件。

进入“File”菜单，选择“New”打开一个新的工作文件。

在Fluent主界面的左侧面板选择“2D”选项卡，然后选择“Viscous”和“Steady”选项后点击“Create/Edit”按钮。

第二步，进入“Grid”界面。

在“Mesh”选项卡中选择“2D Mesh”菜单，选择“Triangle”网格类型。

随后，选择“Mechanical”类型并调整所需参数，包括网格的大小、分辨率、以及其他关键点的划分数量。

最后，点击“Generate Mesh”按钮生成网格。

第三步，设置边界条件。

在Fluent主界面的左侧面板选择“Boundary Conditions”选项卡。

根据需要设置边界条件，包括入口和出口边界、容器壁边界和物体边界。

基本的物理条件包括质量流速、温度和密度。

第四步，设置模拟参数。

在Fluent主界面的左侧面板选择“Solution”选项卡。

首先选择“Viscous”和“Steady”选项，然后在“Methods”菜单中选择“Unsteady”. 调整所需参数并计算时间，包括时间步长和计算时间范围。

第五步，开始求解二维大涡模拟。

在Fluent主界面的左侧面板选择“Compute”选项卡，点击“Start Calculation”按钮开始求解。

第六步，查看二维大涡模拟结果。

在Fluent主界面的左侧面板选择“Graphics”选项卡。

根据需要选择显示不同的结果，包括速度分布、温度变化、实体形态等等。

以上是使用Fluent二维大涡模拟命令的步骤。

通过学习和实践，我们可以使用Fluent来分析和解决各种相关的物理、化学和工程问题。

fluent命令介绍、网格划分、参数使用

第一章Fluent 软件的介绍fluent 软件的组成：软件功能介绍：GAMBIT 专用的CFD 前置处理器(几何/网格生成) Fluent4.5 基于结构化网格的通用CFD 求解器 Fluent6.0 基于非结构化网格的通用CFD 求解器 Fidap 基于有限元方法的通用CFD 求解器 Polyflow 针对粘弹性流动的专用CFD 求解器 Mixsim 针对搅拌混合问题的专用CFD 软件 Icepak专用的热控分析CFD 软件软件安装步骤：step 1: 首先安装exceed软件，推荐是exceed6.2版本，再装exceed3d,按提示步骤完成即可，提问设定密码等，可忽略或随便填写。

step 2: 点击gambit文件夹的setup.exe，按步骤安装；step 3: FLUENT和GAMBIT需要把相应license.dat文件拷贝到FLUENT.INC/license目录下；step 4：安装完之后，把x:\FLUENT.INC\ntbin\ntx86\gambit.exe命令符拖到桌面（x为安装的盘符）；step 5: 点击fluent源文件夹的setup.exe，按步骤安装；step 6: 从程序里找到fluent应用程序，发到桌面上。

注：安装可能出现的几个问题：1.出错信息“unable find/open license.dat"，第三步没执行；2.gambit在使用过程中出现非正常退出时可能会产生*.lok文件，下次使用不能打开该工作文件时，进入x:\FLUENT.INC\ntbin\ntx86\，把*.lok文件删除即可；3.安装好FLUENT和GAMBIT最好设置一下用户默认路径，推荐设置办法，在非系统分区建一个目录，如d:\usersa） win2k用户在控制面板－用户和密码－高级－高级，在使用fluent用户的配置文件修改本地路径为d:\users，重起到该用户运行命令提示符，检查用户路径是否修改；b） xp用户，把命令提示符发送到桌面快捷方式，右键单击命令提示符快捷方式在快捷方式－起始位置加入D:\users,重起检查。

Fluent教程.doc

Fluent 教程1。

启动FLUENT以WINDOWS NT 为内核的操作系统包括WINDOWS 2000 和WINDOWS XP，其启动方式有两种：（1）从WINDOWS 的开始菜单中进行启动，即顺序点击：开始-> 程序-> Fluent Inc. -> FLUENT 6.1就可以启动FLUENT。

（2）从DOS 终端窗口启动，即在命令行中：1）键入“fluent 2d”，启动二维单精度计算。

2）键入“fluent 3d”，启动三维单精度计算。

3）键入“fluent 2ddp”，启动二维双精度计算。

4）键入“fluent 3ddp”，启动三维双精度计算。

如果想启动并行计算模式，可以在上述4 个命令后面加上-tx 参数，其中x 是并行计算的CPU 数量，例如键入“fluent 3d –t3”意思是在三个处理器上运行三维计算。

单精度和双精度求解器在所有的操作系统上都可以进行单精度和双精度计算。

对于大多数情况来说，单精度计算已经足够，但在下面这些情况下需要使用双精度计算：（1）计算域非常狭长（比如细长的管道），用单精度表示节点坐标可能不够精确，这时需要采用双精度求解器。

（2）如果计算域是许多由细长管道连接起来的容器，各个容器内的压强各不相同。

如果某个容器的压强特别高的话，那么在采用同一个参考压强时，用单精度表示其他容器内压强可能产生较大的误差，这时可以考虑使用双精度求解器。

（3）在涉及到两个区域之间存在很大的热交换，或者网格的长细比很大时，用单精度可能无法正确传递边界信息，并导致计算无法收敛，或精度达不到要求，这时也可以考虑采用双精度求解器。

2 计算步骤工作计划确定下来后，就可以按照下面的基本步骤开始计算：（1）定义流场的几何参数并进行网格划分。

（2）启动相关的求解器。

（3）输入网格。

（4）检查网格。

（5）选择求解器格式。

（6）选择求解所用的基本方程：层流还是湍流？有没有化学反应？是否考虑传热？是否需要其它的物理模型，比如是否使用多孔介质模型？是否使用风扇模型？是否使用换热器模型？（7）定义物质属性。

fluent模拟基本步骤及注意事项

二维模拟：一、模拟类型：1、大区域空间速度场模拟计算区域大小设置：迎风面是建筑长度的3倍，背风面是建筑长度的12倍，两侧面是建筑宽度的3倍，高度是建筑高度的4倍。

根据相似理论：l C -几何比例尺速度比例尺：210l C C =υ 风量比例尺：2520l l Q C C C C =⋅=υ 热量比例尺：250l T Q C C C Cq =⋅=∆2、建筑户型温度场、速度场模拟二、基本操作步骤及注意事项：A gambit 建模1、建模：方法一：直接在GAMBIT 建模；方法二：CAD 导入gambit ；1）在CAD 中用PL 线将户型的基本构造画出来，创建为面域；2）输入命令acisoutver ，把‘70’修改为‘30’。

3） “文件”——“输出”——sat 文件4）在gambit 中导入Acis 文件注意：在用PL 线构画户型时，在进口和出口边界（窗户、内户门），要各边界端点连续画线。

2、划分网格：Interval Size ：503、设置边界条件内部开口边界（门）设置为internal ，房间相邻墙壁设置为Wall4、保存文件，并输出mesh 文件B 导入fluent 计算：1、导入mesh 文件2、检查网格3、设置单位gambit 里可以缩小建筑比例建模，在fluent 中设置单位恢复原模型。

4、选择计算模型5、设置材料类型6、设置边界条件7、设置模拟控制条件8、边界初始化9、设置监视窗口10、设置迭代次数进行计算11、结果显示12、保存文件三、需解决问题：1、湍流强度等计算；2、层流湍流界定问题；3、壁面湿度设置问题；四、待提高部分：1、户型流场模拟时，墙壁考虑采用双钱；2、南京理工校区原始模型（不简化）模拟；3、三维模型模拟；五、。

FLUENT算例——TurbulentPipeFlow（LES）圆管湍流流动（大涡模拟）

FLUENT 算例——TurbulentPipeFlow （LES ）圆管湍流流动（⼤涡模拟）Turbulent Pipe Flow (LES) 圆管湍流流动（⼤涡模拟）以ANSYS 17.0为例问题描述考虑通过圆形截⾯直管道的流动问题，圆管直径，长度。

管道进⼝处的平均流速为，假设流体密度为定值，，流体动⼒粘性系数。

那么基于圆管直径、平均流速、流体密度、动⼒粘性系数算得该问题的Reynold数（Re）为接下来咱们⽤ANSYS FLUENT中的LES⽅法来求解该流动问题，绘制在距离进⼝处下游截⾯上随着半径变化的平均速度和均⽅根速度，并⽐较由LES⽅法和⽅法模拟得到的平均速度。

1 预分析和准备⼯作预分析在⼤涡模拟中，瞬时速度被分解为滤波后的分量以及剩余的残差分量，滤波后的速度分量表征了⼤尺度的⾮定常运动。

在LES中，⼤尺度的湍流运动被直接表征，⽽⼩尺度的湍流运动则⽤模型近似。

关于滤波速度的滤波⽅程可以从Navier-Stokes⽅程推出，由于残差操作，动量⽅程中的⾮线性对流项引⼊了⼀个应⼒张量的残差项，该残差应⼒张量需要通过构造模型来完成⽅程组的封闭，⽽FLUENT中提供了从易到难的多种模型。

既然咱们要求解，那么LES就是个⾮定常的模拟过程，需要在时域内向前推进。

为了收集统计平均量，⽐如平均和均⽅根（root mean square（r.m.s.））速度，咱们需要⾸先达到统计上的稳定状态（然后再开展统计平均的处理）。

作为对⽐，模型求得的平均速度也⼀并给出。

关于LES的详细理论和⽅程可以再很多湍流的书籍中找到。

准备⼯作LES是三维⾮定常计算（只能适⽤于三维问题和⾮定常问题），那么计算域是全部的管道。

在打开ANSYS之前，先创建⼀个⽂件夹turbulent_pipe_LES，然后⾥⾯在创建⼀个ICEM⽂件夹和FLUENT⽂件夹，分别⽤来存放ICEM的建模和画⽹格⽂件，以及FLUENT的计算⽂件。

2 构建⼏何模型打开ICEM CFD 17.0软件，在其中完成建模⼯作，咱们计算域是圆管内部流道，也就是⼀个圆柱体，让圆柱体的轴线沿着⽅向，进⼝截⾯位于上，圆⼼位于坐标原点。

大涡模拟的FLUENT算例2D

大涡模拟的FLUENT算例2DTutorial:Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)IntroductionThe purpose of this tutorial is to provide guidelines and recommendations for the basic setup and solution procedure for a typical aeroacoustic application using computational aeroacoustic(CAA)method.In this tutorial you will learn how to:Model a Helmholtz resonator.Use the transient k-epsilon model and the large eddy simulation(LES)model foraeroacoustic application.Set up,run,and perform postprocessing in FLUENT.PrerequisitesThis tutorial assumes that you are familiar with the user interface,basic setup and solution procedures in FLUENT.This tutorial does not cover mechanics of using acoustics model,but focuses on setting up the problem for Helmholtz-Resonator and solving it.It also assumes that you have basic understanding of aeroacoustic physics.If you have not used FLUENT before,it would be helpful to?rst review FLUENT6.3User’s Guide and FLUENT6.3Tutorial Guide.Problem DescriptionA Helmholtz resonator consists of a cavity in a rigid structure that communicates through anarrow neck or slit to the outside air.The frequency of resonance is determined by the mass of air in the neck resonating in conjunction with the compliance of the air in the cavity.The physics behind the Helmholtz resonator is similar to wind noise applications like sun roof bu?eting.We assume that out of the two cavities that are present,smaller one is the resonator.The motion of the?uid takes place because of the inlet velocity of27.78m/s(100km/h).The ?ow separates into a highly unsteady motion from the opening to the small cavity.This unsteady motion leads to a pressure?uctuations.Two monitor points(Point-1and Point-2) act as microphone points to record the generated sound.The acoustic signal is calculated within FLUENT.The?ow exits the domain through the pressure outlet.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA) Preparation1.Copy the?les steady.cas.gz,steady.dat.gz,execute-by-name.scm,stptmstp4.scm,ti-to-scm-jos.scm and stptmstp.txt into your working directory.2.Start the2D double precision(2ddp)version of FLUENT.Setup and SolutionStep1:Grid1.Read the initial case and data?les for steady-state(steady.cas.gz and steady.dat.gz).File?→Read?→Case&Data...Ignore the warning that is displayed in the FLUENT console while reading these?les.2.Keep default scale for the grid.Grid?→Scale...3.Display the grid and observe the locations of the two monitor points,Point-1andPoint-2(Figure1).Figure1:Graphics Display of the Grid4.Display and observe the contours of static pressure(Figure2)and velocity magnitude(Figure3)for the initial steady-state solution.Display?→Contours..Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure2:Contours of Static Pressure(Steady State)Figure3:Contours of Velocity Magnitude(Steady State)Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA) Step2:Models1.Select unsteady solver.De?ne?→Models?→Solver...(a)Select Unsteady in the Time list.(b)Select2nd-order-implicit in the Unsteady formulation list.(c)Retain the default settings for other parameters.(d)Click OK to close the Solver panel.2.De?ne the viscous model.De?ne?→Models?→Viscous...(a)Select Non-Equilibrium Wall Functions in the Near-Wall Treatment list.(b)Retain the default settigns for other parameters.(c)Click OK to close the Viscous Model panel.Near-Wall Treatment predicts good separation and re-attachment points.Step3:MaterialsDe?ne?→Materials...1.Select ideal-gas from the Density drop-down list.2.Retain the default values for other parameters.3.Click Change/Create and close the Materials panel.Ideal gas law is good in predicting the small changes in the pressure.Step4:Solution1.Monitor the static pressure on point-1and point-2.Solve?→Monitors?→Surface...(a)Enter2for the Surface Monitors.(b)Enable Plot and Print options for monitor-1and monitor-2.(c)Select Time Step from the When list.(d)Click De?ne...for monitor-1to open De?ne Surface Monitor panel.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)i.Select Vertex Average from the Report Type drop-down list.ii.Select Flow Time from the X Axis drop-down list.iii.Enter1for Plot Window.iv.Select point-1from the Surfaces selection list.(e)Similarly,specify the surface monitor parameters for point-2.2.Start the calculations using the following settings.Solve?→Iterate...(a)Enter3e-04s for Time Step Size.The expected time step size for this problem is of the size of about1/10th of thetime period.The time period depends on the frequency(f)which is calculatedusing the following equation:f=c2πSV[L+π2.D h2]where,c=Speed of soundS=Area of the ori?ce of the resonatorV=Volume of the resonatorL=Length of the connection between the resonator and the free?ow areaD h=Hydraulic diameter of the ori?ceFor this geometry,the estimated frequency is about120Hz.(b)Enter250for the Number of Time Steps.(c)Enter50for Max Iterations per Time Step.(d)Click Apply.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)(e)Read the scheme?le(stptmstp4.scm).File?→Read?→Sc heme...This?le activates a alternative convergence criteria.For acoustic simulationswith CAA it is obligatory that the pressure is completely converged at the recieverposition.FLUENT compares the monitor quantities within the last n-de?ned it-erations to judge if the deviation is smaller than a y-de?ned deviation.(f)Specify the number of previous iterations from which monitor values of eachquantity used are saved and compared to the current(latest)value(include theparanthesis):(set!stptmstp-n5)(g)Specify the relative(the smaller of two values in any comparison)di?erenceby which any of the older monitor values(for a selected monitor qauntity)maydi?er from the newest value:(set!stptmstp-maxrelchng1.e-02)(h)De?ne the execute commands.Solve?→Execut e Commandsi.Enter(stptmstp-resetvalues)for the?rst command and selectTime Stepfrom the drop-down list.ii.Enter(stptmstp-chckcnvrg"/report/surface-integrals vertex-avg point-1 ()pressure")and select Iteration from the drop-down list.iii.Click OK.(i)Click Iterate to start the calculations.The iterations will take a long time to complete.You can skip this simulation af-ter few time steps and read the?les(transient.cas.gz and transient.dat.gz)provided with this tutorial.These?les contain the data for the?ow time of0.22seconds.As seen in Figures4and5,no pressure?uctuations are present at thisstage.The oscillations of the static pressure at both monitor points has reacheda constant value.The RANS-simulation is a good starting point for Large Eddy Simulation.Ifyou choose to use the steady solution as initial condition for LES,use the TUIcommand/solve/initialize/init-instantaneous-vel provides to get a more realisticinstantaneous velocity?eld.The usage of LES for acoustic simulations is obliga-tory.The next two pictures compare the static pressure obtained with RANS andLarge Eddy Simulation for a complete simulation until0.525seconds.Obviously,the k-epsilon model underpredicts the strong pressure oscillation after reachinga dynamically steady state(>0.3s)due to its dissipative character.Under-predicted pressure oscillations lead to underpredicted sound pressure level whichmeans the acoustic noise is more gentle.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure4:Convergence History of Static Pressure on Point-1(Transient)Figure5:Convergence History of Static Pressure on Point-2(Transient)Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA) Step5:Enable Large Eddy Simulation1.Enter the following TUI command in the FLUENT console:(rpsetvar’les-2d?#t)2.Enable large eddy simulation e?ects.The k-epsilon model cannot resolve very small pressure?uctuations for aeroacousticdue to its dissipative e Large Eddy Simulation to overcome this problem.De?ne?→Models?→Viscous...(a)Enable Large Eddy Simulation(LES)in the Model list.(b)Enable WALE in the Subgrid-Scale Model list.(c)Click OK to close the Viscous Model panel.An Information panel will appear,warning about bounded central-deferencing be-ing default for momentum with LES/DES.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)(d)Click OK to close the Information panel.3.Retain default discretization schemes and under-relaxation factors.Solve?→Controls?→Solution...4.Enable writing of two surface monitors and specify?lenames as monitor-les-1.out andmonitor-les-2.out for monitor plots of point-1and point-2respectively.Solve?→Monitors?→Surface...To account for stochastic components of the?ow,FLUENT provides two algorithms.These algorithms model the?uctuating velocity at velocity inlets.With the spec-tral synthesizer the?uctuating velocity components are computed by synthesizing adivergence-free velocity-vector?eld from the summation of Fourier harmonics.5.Enable the spectral synthesizer.De?ne?→Boundary Conditions...(a)Select inlet in the Zone list and click Set....i.Select Spectral Synthesizer from the Fluctuating VelocityAlgorithm drop-downlist.ii.Retain the default values for other parameters.iii.Click OK to close the Velocity Inlet panel.(b)Close the Boundary Conditions panel.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA) Typically it takes a long time to get a dynamically steady state.Additionally,thesimulated(and recorded for FFT)?ow time depends on the minimum frequency in thefollowing relationship:flowtime=10minimumfrequency(1)The standard transient scheme(iterative time advancement)requires a considerable amount of computaional e?ort due to a large number of outer iterations performed for each time-step.To accelerate the simulation,the NITA(non-iterative time advance-ment)scheme is an alternative.6.Set the solver parameters.De?ne?→Models?→Solver...(a)Enable Non-Iterative Time Advancement in the Transient Controls list.(b)Click OK to close the Solver panel.7.Set the solution parameters.Solve?→Controls?→Solution...(a)Select Fractional Step from the Pressure-Velocity Coupling drop-down list.(b)Click OK to close the Solution Controls panel.8.Disable both the execute commands.Solve?→Execute Commands...9.Continue the simulation with the same time step size for1500time steps to get adynamically steady solution.10.Write the case and data?les(unsteady-?nal.cas.gz and unsteady-?nal.dat.gz).File?→Write?→Case&Data...Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure6:Convergence History of Static Pressure on Point-1(Transient)Figure7:Convergence History of Static Pressure on Point-2(Transient)Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA) Step6:Postprocessing1.Display the contours of static pressure to visualize the eddies near the ori?ce.2.Enable the acoustics model.De?ne?→Models?→Acoustics...(a)Enable Ffowcs-Williams&Hawkings from the Model selection list.(b)Retain the default value of2e-05Pa for Reference Acoustic Pressure.To specify a value for the acoustic reference pressure,it is necessary to activatethe acoustic model before starting postprocessing.(c)Retain default settings for other parameters.(d)Click OK to accept the settings.A Warning dialog box appears.This is an informative panel and will not a?ectthe postprocessing results.(e)Click OK to acknowledge the information and close the Warning panel.3.Plot the sound pressure level(SPL).Plot?→FFT...Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)(a)Click Load Input File...button.(b)Select monitor plot?le for Point-1(monitor-les-1.out).(c)Click Plot/Modify Input Signal....i.Select Clip to Range,in the Options list.ii.Enter0.3for Min and0.5for Max in the X Axis Range group box.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)iii.Select Hanning in the Window drop-down list.Hanning shows good performance in frequency resolution.It cuts the timerecord more smoothly,eliminating discontinuities that occur when data iscut o?.iv.Click Apply/Plot and close the Plot/Modify Input Signal panel.(d)Select Sound Pressure Level(dB)from the Y Axis Function drop-down list.(e)Select Frequency(Hz)in the X Axis Function drop-down list.(f)Click Plot FFT to visualize the frequency distribution at Point-1.(g)Select Write FFT to File in the Options list.Note:Plot FFT button will change to Write FFT.(h)Click Write FFT and specify the name of the FFT?le in the resulting Select Filepanel.(i)Similarly write the FFT?le for monitor plot for point-2(Figure9).Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure8:Spectral Analysis of Convergence History of Static Pressure on Point-1Figure9:Spectral Analysis of Convergence History of Static Pressure on Point-2Modeling Aeroacoustics for a Helmholtz Resonator Using theDirect Method(CAA) In Figures8and9,the sound pressure level(SPL)peak occurs at125Hz which isclose to the analytical estimation.Considering that this tutorial uses a slightly largetime step and a2D geometry,the result is?ne.pare the frequency spectra at point-1and point-2.Plot?→File...(a)Click Add...and select two FFT?les(point-1-fft.xy and point-2-fft.xy)that you have saved in the previous step.(b)Click Plot to visualize both spectra in the same window(Figure10).Note that the peak for Point-1is a little higher than for Point-2.This is due to the dissipative behaviour of the sound in the domain.The bigger the distance between the reciever point and the noise source,the bigger is the dissipation of sound.This is the reason,why we use CAA method only for near?eld calculations.Figure10:Comparison of Frequency Spectra at Point-1and Point-2A second issue is the dissipation of sound due to the in?uence of the grid size.This appliesespecially for which the wave lengths are very short.Thus,a too coarse mesh is not capable of resolving high frequencies correctly.In the present example,the mesh is rather coarse in the far-?eld.Thus,the discrepancy between both spectra is more evident in the high frequency range.This behaviour can be seen in Figure11.For high frequencies,the monitor for Point-1generates much fewer noise than monitor for Point-2due to coarse grid resolution.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure11:Spectral Analysis of Convergence history of Static Pressure The deviation of sound pressure level between the?rst two maximum peaks(50Hz and132 Hz)is quite small.Thepostprocessing function magnitude in fourier transform panel is similar to the root mean square value(RMS)of the static pressure at these frequencies.We can use the RMS value to derive the amplitude of the pressure?uctuation which is responsible for the SPL-peak.The resolution of frequency spectra is limited by the temporal discretization.With the temporal discretization,the maximum frequency isf max=12 t(2)This frequency is de?ned as Nyquist frequency.It is the maximum educible frequency.T o resolve up to f max the maximum allowable time step size isf max=12×f max(3)Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure12:Spectral Analysis of Convergence History of Static Pressure on Point-1An instability of the?uid motion coupled with an acoustic resonance of the cavity(helmholtz resonator)produces large pressure?uctuations(at132Hz).Compared to this dominanthelmholtz resonance the pressure?uctuation at50Hz is quite small.Modeling Aeroacoustics for a Helmholtz Resonator Using the Direct Method(CAA)Figure13:Spectral Analysis of Convergence History of Static Pressure on Point-2SummaryAeroacoustic simulation of Helmholtz resonator has been performed using k-epsilon model and Large Eddy Simulation model.The advantage of using LES model has been demon-strated.You also learned how the sound dissipation occurs in the domain by monitoring sound pressure level at two di?erent points in the domain.The importance of using CAA method has also been explained.。

Fluent模型使用技巧

1.多相流动模式我们可以根据下面的原则对多相流分成四类：•气-液或者液-液两相流：o气泡流动：连续流体中的气泡或者液泡。

o液滴流动：连续气体中的离散流体液滴。

o活塞流动:在连续流体中的大的气泡o分层自由面流动：由明显的分界面隔开的非混合流体流动。

•气-固两相流：o充满粒子的流动：连续气体流动中有离散的固体粒子。

o气动输运：流动模式依赖诸如固体载荷、雷诺数和粒子属性等因素。

最典型的模式有沙子的流动，泥浆流，填充床，以及各向同性流。

o流化床：由一个盛有粒子的竖直圆筒构成，气体从一个分散器导入筒内。

从床底不断充入的气体使得颗粒得以悬浮。

改变气体的流量，就会有气泡不断的出现并穿过整个容器，从而使得颗粒在床内得到充分混合。

•液-固两相流o泥浆流：流体中的颗粒输运。

液-固两相流的基本特征不同于液体中固体颗粒的流动。

在泥浆流中，Stokes数通常小于1。

当Stokes数大于1时，流动成为流化（fluidization）了的液-固流动。

o水力运输:在连续流体中密布着固体颗粒o沉降运动:在有一定高度的成有液体的容器内，初始时刻均匀散布着颗粒物质。

随后，流体将会分层，在容器底部因为颗粒的不断沉降并堆积形成了淤积层，在顶部出现了澄清层，里面没有颗粒物质，在中间则是沉降层，那里的粒子仍然在沉降。

在澄清层和沉降层中间，是一个清晰可辨的交界面。

•三相流(上面各种情况的组合)各流动模式对应的例子如下：•气泡流例子：抽吸，通风，空气泵，气穴，蒸发，浮选，洗刷•液滴流例子：抽吸，喷雾，燃烧室，低温泵，干燥机，蒸发，气冷，刷洗•活塞流例子：管道或容器内有大尺度气泡的流动•分层自由面流动例子：分离器中的晃动，核反应装置中的沸腾和冷凝•粒子负载流动例子：旋风分离器，空气分类器，洗尘器，环境尘埃流动•风力输运例子：水泥、谷粒和金属粉末的输运•流化床例子：流化床反应器，循环流化床•泥浆流例子:泥浆输运，矿物处理•水力输运例子：矿物处理，生物医学及物理化学中的流体系统•沉降例子：矿物处理2.多相流模型FLUENT中描述两相流的两种方法:欧拉一欧拉法和欧拉一拉格朗日法，后面分别简称欧拉法和拉格朗日法。

fluent命令介绍、网格划分、参数使用

第一章Fluent 软件的介绍fluent 软件的组成：软件功能介绍：GAMBIT 专用的CFD 前置处理器(几何/网格生成) Fluent4.5 基于结构化网格的通用CFD 求解器 Fluent6.0 基于非结构化网格的通用CFD 求解器 Fidap 基于有限元方法的通用CFD 求解器 Polyflow 针对粘弹性流动的专用CFD 求解器 Mixsim 针对搅拌混合问题的专用CFD 软件 Icepak专用的热控分析CFD 软件软件安装步骤：step 1: 首先安装exceed软件，推荐是exceed6.2版本，再装exceed3d,按提示步骤完成即可，提问设定密码等，可忽略或随便填写。

step 2: 点击gambit文件夹的setup.exe，按步骤安装；step 3: FLUENT和GAMBIT需要把相应license.dat文件拷贝到FLUENT.INC/license目录下；step 4：安装完之后，把x:\FLUENT.INC\ntbin\ntx86\gambit.exe命令符拖到桌面（x为安装的盘符）；step 5: 点击fluent源文件夹的setup.exe，按步骤安装；step 6: 从程序里找到fluent应用程序，发到桌面上。

注：安装可能出现的几个问题：1.出错信息“unable find/open license.dat"，第三步没执行；2.gambit在使用过程中出现非正常退出时可能会产生*.lok文件，下次使用不能打开该工作文件时，进入x:\FLUENT.INC\ntbin\ntx86\，把*.lok文件删除即可；3.安装好FLUENT和GAMBIT最好设置一下用户默认路径，推荐设置办法，在非系统分区建一个目录，如d:\usersa） win2k用户在控制面板－用户和密码－高级－高级，在使用fluent用户的配置文件修改本地路径为d:\users，重起到该用户运行命令提示符，检查用户路径是否修改；b） xp用户，把命令提示符发送到桌面快捷方式，右键单击命令提示符快捷方式在快捷方式－起始位置加入D:\users,重起检查。

史上Fluent最详细操作步骤一看就懂

Fluent简单分析教程第1步双击运行Fluent，首先出现如下界面，对于二维模型我们可以选择2d（单精度）或2ddp（双精度）进行模拟，通常选择2d即可。

Mode选择缺省的Full Simulation即可。

点击“Run”。

然后进入如下图示意界面：第2步：与网格相关的操作1.读入网格文件car1.mesh操作如下图所示：打开的“Select File”对话框如图所示：（1）找到网格文件E:\gfiles\car1.mesh;（2）点击OK，完成输入网格文件的操作。

注意：FLUENT读入网格文件的同时，会在信息反馈窗口显示如下信息：其中包括节点数7590等，最后的Done表示读入网格文件成功。

2.网格检查：操作如下图所示：FLUENT在信息反馈窗口显示如下信息：注意：（1）网格检查列出了X,Y的最小和最大值；（2）网格检查还将报告出网格的其他特性，比如单元的最大体积和最小体积、最大面积和最小面积等；（3）网格检查还会报告出有关网格的任何错误，特别是要求确保最小体积不能是负值，否则FLUENT无法进行计算。

3.平滑（和交换）网格这一步是为确保网格质量的操作。

操作：→Smooth/Swap...打开“Smooth/Swap Grid”对话框如图所示：（1）点击Smooth按钮，再点击Swap，重复上述操作，直到FLUENT 报告没有需要交换的面为止。

如图所示：（2）点击Close按钮关闭对话框。

注意：这一功能对于三角形单元来说尤为重要。

4.确定长度单位操作如下图所示：打开“Scale Grid”对话框如图所示：（1）在单位转换（Units Conversion）栏中的（Grid Was Created In）网格长度单位右侧下拉列表中选择m；（2）看区域的范围是否正确，如果不正确，可以在Scale Factors 的X和Y中分别输入值10，然后点击“Scale”或“Unscale”即可；（3）点击Scale；（4）点击Close关闭对话框。

fluent命令介绍、网格划分、参数使用

第一章Fluent 软件的介绍fluent 软件的组成：软件功能介绍：GAMBIT 专用的CFD 前置处理器(几何/网格生成) Fluent4.5 基于结构化网格的通用CFD 求解器 Fluent6.0 基于非结构化网格的通用CFD 求解器 Fidap 基于有限元方法的通用CFD 求解器 Polyflow 针对粘弹性流动的专用CFD 求解器 Mixsim 针对搅拌混合问题的专用CFD 软件 Icepak专用的热控分析CFD 软件软件安装步骤：step 1: 首先安装exceed软件，推荐是exceed6.2版本，再装exceed3d,按提示步骤完成即可，提问设定密码等，可忽略或随便填写。

step 2: 点击gambit文件夹的setup.exe，按步骤安装；step 3: FLUENT和GAMBIT需要把相应license.dat文件拷贝到FLUENT.INC/license目录下；step 4：安装完之后，把x:\FLUENT.INC\ntbin\ntx86\gambit.exe命令符拖到桌面（x为安装的盘符）；step 5: 点击fluent源文件夹的setup.exe，按步骤安装；step 6: 从程序里找到fluent应用程序，发到桌面上。

注：安装可能出现的几个问题：1.出错信息“unable find/open license.dat"，第三步没执行；2.gambit在使用过程中出现非正常退出时可能会产生*.lok文件，下次使用不能打开该工作文件时，进入x:\FLUENT.INC\ntbin\ntx86\，把*.lok文件删除即可；3.安装好FLUENT和GAMBIT最好设置一下用户默认路径，推荐设置办法，在非系统分区建一个目录，如d:\usersa） win2k用户在控制面板－用户和密码－高级－高级，在使用fluent用户的配置文件修改本地路径为d:\users，重起到该用户运行命令提示符，检查用户路径是否修改；b） xp用户，把命令提示符发送到桌面快捷方式，右键单击命令提示符快捷方式在快捷方式－起始位置加入D:\users,重起检查。

Fluent二维波浪模拟教程

Fluent二维波浪模拟教程Tutorial10.Simulation of Wave Generation in a TankIntroductionThe purpose of this tutorial is to illustrate the setup and solution of the2D laminar?uid ?ow in a tank with oscillating motion of a wall.The oscillating motion of a wall can generate waves in a tank partially?lled with a liquid and open to atmosphere.Smooth waves can be generated by setting appropriate frequency and amplitude.One of the tank walls is moved to and fro by specifying a sinusoidal motion.In this tutorial you will learn how to:Read an existing mesh?le in FLUENT.Check the grid for dimensions and quality.Add new?uid in the materials list.Set up a multiphase?ow problem.Use the dynamic mesh model.Set up an animation using Execute Commands panel.PrerequisitesThis tutorial assumes that you have little experience with FLUENT but are familiar with the interface.Problem DescriptionIn this tutorial,we consider a rectangular tank with a length(L)of15m and width(W) of0.8m(Figure10.1).The left wall is assigned a motion with sinusoidal time variation.The top wall is open to atmosphere and thus maintained at atmospheric pressure.The ?ow is assumed to be laminar.Simulation of Wave Generation in a TankFigure10.1:Problem SchematicPreparation1.Copy the mesh?le,wave.msh and libudf folder to your working directory.2.Start the2D double precision solver of FLUENT.Setup and SolutionStep1:Grid1.Read the grid?le,wave.msh.File?→Read?→Case...FLUENT will read the mesh?le and report the progress in the console window.2.Check the grid.Grid?→CheckThis procedure checks the integrity of the mesh.Make sure the reported minimumvolume is a positive number.3.Check the scale of the grid.Grid?→Scale...Simulation of Wave Generation in a Tank Check the domainextents to see if they correspond to the actual physical dimensions.If not,the grid has to be scaled with proper units.4.Display the grid(Figure10.2).Display?→Grid...(a)Click Colors....The Grid Colors panel opens.i.Under Options,enable Color by ID.ii.Click Close.(b)In the Grid Display panel,click Display(c)Zoom in near the moving-wall(Figure10.3). Simulation of Wave Generation in a TankFigure10.2:Grid DisplayFigure10.3:Grid Display(Close-up of moving-wall) Simulation of Wave Generation in a TankStep2:Models1.Specify the solver settings.De?ne?→Models?→Solver...(a)Under Time,enable Unsteady(b)Under Transient Controls,enable Non-Iterative Time Advancement.(c)Click OK.2.Enable VOF multiphase model.De?ne?→Models?→Multiphase...Simulation of Wave Generation in a Tank(a)Under Model,enable Volume of Fluid.The panel expands to show the other settings related to VOF model.Retainthe other settings as default.(b)Click OK.Step3:MaterialsDe?ne?→Materials...1.Add liquid water to the list of?uid materials by copying it from the materialsdatabase.Simulation of Wave Generation in a Tank(a)Click Fluent Database....Fluent Database Materials panel opens.Simulation of Wave Generation in a Tanki.Select water-liquid(h2o)from the Fluent Fluid Materials list. Scroll down to view water-liquid.ii.Click Copy and close the panel.(b)Click Change/Create and close the panel.Step4:PhasesDe?ne?→Phases...1.Set air as primary phase and water as secondary phase.(a)Under Phase,select phase-1.The Type will be shown as primary-phase.(b)Click Set....i.Change Name to air.ii.Select air in the Phase Material drop-down list.iii.Click OK.(c)Similarly,change the Name of phase-2to water and set its Type to water-liquid.(d)Close the Phases panel.Simulation of Wave Generation in a TankStep5:Operating ConditionsDe?ne?→Operating Conditions...1.Set the gravitational acceleration.(a)Enable Gravity.(b)Under Gravitational Acceleration,set Y to-9.81m/s2.As the tank bottom is perpendicular to Y axis,gravity points in the negativeY direction.2.Set the operating density.(a)Under Variable-Density Parameters,enable Speci?ed Operating Density.(b)Retain the default density of1.225kg/m3.Set the operating density to the density of the lighter phase.This excludesthe build-up of hydrostatic pressure within the lighter phase,improving theround-o?accuracy for the momentum balance.3.Set the reference pressure location.(a)Under Reference Pressure Location,retain the default value of zero for both Xand Y.This location corresponds to a region where the?uid willalways be100%ofone of the phases(water).If it is not,it is recommended to change the regionto a appropriate location where the pressure value does not change much overtime.This condition is essential for smooth and rapid convergence.4.Click OK to accept the settings and close the panel.Simulation of Wave Generation in a TankStep6:Boundary ConditionsFLUENT maintains zero velocity condition on all the walls.Also,the pressure condition for outlet boundary at the top is set by default to zero gauge(or atmospheric).Hence, there is no need to change the boundary conditions.Retain all the boundary conditions as default.Step7:UDF LibraryDe?ne?→User-De?ned?→Functions?→Compiled...1.Click Load to load the UDF library.The sinusoidal wall motion will be assigned using user de?ned function.A compiledUDF library named libudf is created for this purpose.Step8:Dynamic Mesh Model1.Set the dynamic mesh parameters.De?ne?→Dynamic Mesh?→Parameters...Simulation of Wave Generation in a Tank(a)Under Models,enable Dynamic Mesh.The panel expands.(b)Under Mesh Methods,disable Smoothing and enable Layering.(c)Under the Layering tab,set Collapse Factor to0.4.(d)Click OK.2.Set the dynamic mesh zones.De?ne?→Dynamic Mesh?→Zones...(a)Under Zone Names,select moving-wall.(b)Under Type,retain the default selection of Rigid Body.(c)Under Meshing Options tab,set Cell Height to0.008m. This is the average size of the cell normal to the moving wall.(d)Click Create and close the panel.Step9:Solution1.Retain the default solution controls.Solve?→Controls?→Solution...Simulation of Wave Generation in a Tank2.Initialize the?ow.Solve?→Initialize?→Initialize...(a)Click Init and close the panel.The complete domain is now initialized with air.The water level required atstart(t=0)can be patched.3.Create a register marking the region of initial water level.Adapt?→Region...Simulation of Wave Generation in a Tank(a)Set X Max to be15m.(b)Set Y Max to be0.5m.(c)Click Mark and close the panel.FLUENT displays the following message in the console:8510cells marked for re?nement,0cells marked for coarsening.4.Patch the initial water level.Solve?→Initialize?→Patch...(a)Under Registers to Patch,select hexahedron-r0.(b)Under Phase,select water.(c)Under Variable,select Volume Fraction.(d)Set Value to1.(e)Click Patch and close the panel.Simulation of Wave Generation in a Tank5.Display the zone motion to check the movement of moving-wall.(a)Display the grid(Figure10.4).Display?→Grid...i.Under Surfaces,deselect default-interior.Zoom-in the graphics window to get the view as shown in Figure10.4.ii.Click Display.Figure10.4:Grid Display Outline at t=0(b)Display the zone motion.Display?→Zone Motion...Simulation of Wave Generation in a Tanki.Under Motion History Integration,set Time Step to0.001. ii.Set Number of Steps to300.iii.Click Integrate.iv.Under Preview Controls,set Time Step to0.001.v.Set Number of Steps to300.vi.Click Preview to observe the wall motion.vii.Close the Zone Motion panel.6.View the contours of volume fraction for water(Figure10.5).Display?→Contours...(a)Select Phases...and Volume Fraction in the Contours of drop-down lists.(b)Under Phase,select water.(c)Under Options,enable Filled.(d)Click Display and close the panel.Simulation of Wave Generation in a TankFigure10.5:Contours of Volume Fraction for Water7.Enable the plotting of residuals during the calculation. Solve?→Monitors?→Residuals...(a)Under Options,enable Plot.(b)Under Plotting,set Iterations to10.This will display residuals for only the last10iterations.(c)Click OK.Simulation of Wave Generation in a Tank8.Set hardcopy settings.File?→Hardcopy...(a)Under Format,select TIFF.(b)Under Coloring,select Color.(c)Click Apply.(d)Click Preview.The background of graphics window is changed to white.FLUENT will displaya question dialog box asking you whether to reset the window.(e)Click Yes in the Question dialog box.(f)Close the panel.9.Set the commands to capture the images of contours.You need to use Text User Interface(TUI)commands to achieve this.For most of the graphical commands,corresponding TUI commands are available.Solve?→Execute Commands...Simulation of Wave Generation in a Tank(a)Set the number of De?ned Commands to3.(b)Enable On option for all the commands.(c)Under Every,set7for all the commands.(d)Under When,set Time Step for all the commands.(e)For command-1,specify the Command as:display set-window1This command will make the window-1active.(f)For command-2,specify the Command as:display contour water vof01This command will display the contours of water volume fraction in the activewindow.(g)For command-1,specify the Command as:display hard-copy"vof-%t.tif"This command will save the image in the TIF format.The%t option gets replaced with the time step number,when the image?leis saved.The TIF?les saved can then be used to create a movie.For theinformation on converting TIF?le to an animation?le,refer to/cfm/graphics01.htm(h)Click OK to accept the settings and close the panel.10.Set the surface monitors.Solve?→Monitors?→Surface...(a)Increase the number of Surface Monitors to1.(b)Enable Plot for monitor-1.(c)Under Every,select Time Step.(d)Click on De?ne...next to monitor-1.Simulation of Wave Generation in a Tank(e)Select Area Weighted Average in the Report Type drop-down list.(f)Select Grid and X-Coordinate in the Report of drop-down list.(g)Under Surfaces,select moving-wall.(h)Click OK to close both the panels.11.Save the case and data?les(wave-init.cas.gz and wave-init.dat.gz).File?→Write?→Case&Data...Retain the default Write Binary Files option so that you can write a binary?le.The .gz extension will save zipped?les on both,Windows and UNIX platforms.。

Fluent二维波浪模拟教程

Tutorial10.Simulation of Wave Generation in a TankIntroductionThe purpose of this tutorial is to illustrate the setup and solution of the2D laminarﬂuid ﬂow in a tank with oscillating motion of a wall.The oscillating motion of a wall can generate waves in a tank partiallyﬁlled with a liquid and open to atmosphere.Smooth waves can be generated by setting appropriate frequency and amplitude.One of the tank walls is moved to and fro by specifying a sinusoidal motion.In this tutorial you will learn how to:•Read an existing meshﬁle in FLUENT.•Check the grid for dimensions and quality.•Add newﬂuid in the materials list.•Set up a multiphaseﬂow problem.•Use the dynamic mesh model.•Set up an animation using Execute Commands panel.PrerequisitesThis tutorial assumes that you have little experience with FLUENT but are familiar with the interface.Problem DescriptionIn this tutorial,we consider a rectangular tank with a length(L)of15m and width(W) of0.8m(Figure10.1).The left wall is assigned a motion with sinusoidal time variation.The top wall is open to atmosphere and thus maintained at atmospheric pressure.The ﬂow is assumed to be laminar.Simulation of Wave Generation in a TankFigure10.1:Problem SchematicPreparation1.Copy the meshﬁle,wave.msh and libudf folder to your working directory.2.Start the2D double precision solver of FLUENT.Setup and SolutionStep1:Grid1.Read the gridﬁle,wave.msh.File−→Read−→Case...FLUENT will read the meshﬁle and report the progress in the console window.2.Check the grid.Grid−→CheckThis procedure checks the integrity of the mesh.Make sure the reported minimumvolume is a positive number.3.Check the scale of the grid.Grid−→Scale...Simulation of Wave Generation in a Tank Check the domain extents to see if they correspond to the actual physical dimensions.If not,the grid has to be scaled with proper units.4.Display the grid(Figure10.2).Display−→Grid...(a)Click Colors....The Grid Colors panel opens.i.Under Options,enable Color by ID.ii.Click Close.(b)In the Grid Display panel,click Display(c)Zoom in near the moving-wall(Figure10.3).Simulation of Wave Generation in a TankFigure10.2:Grid DisplayFigure10.3:Grid Display(Close-up of moving-wall)Simulation of Wave Generation in a TankStep2:Models1.Specify the solver settings.Deﬁne−→Models−→Solver...(a)Under Time,enable Unsteady(b)Under Transient Controls,enable Non-Iterative Time Advancement.(c)Click OK.2.Enable VOF multiphase model.Deﬁne−→Models−→Multiphase...Simulation of Wave Generation in a Tank(a)Under Model,enable Volume of Fluid.The panel expands to show the other settings related to VOF model.Retainthe other settings as default.(b)Click OK.Step3:MaterialsDeﬁne−→Materials...1.Add liquid water to the list ofﬂuid materials by copying it from the materialsdatabase.Simulation of Wave Generation in a Tank(a)Click Fluent Database....Fluent Database Materials panel opens.Simulation of Wave Generation in a Tanki.Select water-liquid(h2o<l>)from the Fluent Fluid Materials list.Scroll down to view water-liquid.ii.Click Copy and close the panel.(b)Click Change/Create and close the panel.Step4:PhasesDeﬁne−→Phases...1.Set air as primary phase and water as secondary phase.(a)Under Phase,select phase-1.The Type will be shown as primary-phase.(b)Click Set....i.Change Name to air.ii.Select air in the Phase Material drop-down list.iii.Click OK.(c)Similarly,change the Name of phase-2to water and set its Type to water-liquid.(d)Close the Phases panel.Simulation of Wave Generation in a TankStep5:Operating ConditionsDeﬁne−→Operating Conditions...1.Set the gravitational acceleration.(a)Enable Gravity.(b)Under Gravitational Acceleration,set Y to-9.81m/s2.As the tank bottom is perpendicular to Y axis,gravity points in the negativeY direction.2.Set the operating density.(a)Under Variable-Density Parameters,enable Speciﬁed Operating Density.(b)Retain the default density of1.225kg/m3.Set the operating density to the density of the lighter phase.This excludesthe build-up of hydrostatic pressure within the lighter phase,improving theround-oﬀaccuracy for the momentum balance.3.Set the reference pressure location.(a)Under Reference Pressure Location,retain the default value of zero for both Xand Y.This location corresponds to a region where theﬂuid will always be100%ofone of the phases(water).If it is not,it is recommended to change the regionto a appropriate location where the pressure value does not change much overtime.This condition is essential for smooth and rapid convergence.4.Click OK to accept the settings and close the panel.Simulation of Wave Generation in a TankStep6:Boundary ConditionsFLUENT maintains zero velocity condition on all the walls.Also,the pressure condition for outlet boundary at the top is set by default to zero gauge(or atmospheric).Hence, there is no need to change the boundary conditions.Retain all the boundary conditions as default.Step7:UDF LibraryDeﬁne−→User-Deﬁned−→Functions−→Compiled...1.Click Load to load the UDF library.The sinusoidal wall motion will be assigned using user deﬁned function.A compiledUDF library named libudf is created for this purpose.Step8:Dynamic Mesh Model1.Set the dynamic mesh parameters.Deﬁne−→Dynamic Mesh−→Parameters...(a)Under Models,enable Dynamic Mesh.The panel expands.(b)Under Mesh Methods,disable Smoothing and enable Layering.(c)Under the Layering tab,set Collapse Factor to0.4.(d)Click OK.2.Set the dynamic mesh zones.Deﬁne−→Dynamic Mesh−→Zones...(a)Under Zone Names,select moving-wall.(b)Under Type,retain the default selection of Rigid Body.(c)Under Meshing Options tab,set Cell Height to0.008m.This is the average size of the cell normal to the moving wall.(d)Click Create and close the panel.Step9:Solution1.Retain the default solution controls.Solve−→Controls−→Solution...Solve−→Initialize−→Initialize...(a)Click Init and close the panel.The complete domain is now initialized with air.The water level required at start(t=0)can be patched.3.Create a register marking the region of initial water level.Adapt−→Region...(a)Set X Max to be15m.(b)Set Y Max to be0.5m.(c)Click Mark and close the panel.FLUENT displays the following message in the console:8510cells marked for reﬁnement,0cells marked for coarsening.4.Patch the initial water level.Solve−→Initialize−→Patch...(a)Under Registers to Patch,select hexahedron-r0.(b)Under Phase,select water.(c)Under Variable,select Volume Fraction.(d)Set Value to1.(e)Click Patch and close the panel.5.Display the zone motion to check the movement of moving-wall.(a)Display the grid(Figure10.4).Display−→Grid...i.Under Surfaces,deselect default-interior.Zoom-in the graphics window to get the view as shown in Figure10.4.ii.Click Display.Figure10.4:Grid Display Outline at t=0(b)Display the zone motion.Display−→Zone Motion...i.Under Motion History Integration,set Time Step to0.001.ii.Set Number of Steps to300.iii.Click Integrate.iv.Under Preview Controls,set Time Step to0.001.v.Set Number of Steps to300.vi.Click Preview to observe the wall motion.vii.Close the Zone Motion panel.6.View the contours of volume fraction for water(Figure10.5).Display−→Contours...(a)Select Phases...and Volume Fraction in the Contours of drop-down lists.(b)Under Phase,select water.(c)Under Options,enable Filled.(d)Click Display and close the panel.Figure10.5:Contours of Volume Fraction for Water7.Enable the plotting of residuals during the calculation.Solve−→Monitors−→Residuals...(a)Under Options,enable Plot.(b)Under Plotting,set Iterations to10.This will display residuals for only the last10iterations.(c)Click OK.8.Set hardcopy settings.File−→Hardcopy...(a)Under Format,select TIFF.(b)Under Coloring,select Color.(c)Click Apply.(d)Click Preview.The background of graphics window is changed to white.FLUENT will displaya question dialog box asking you whether to reset the window.(e)Click Yes in the Question dialog box.(f)Close the panel.9.Set the commands to capture the images of contours.You need to use Text User Interface(TUI)commands to achieve this.For most of the graphical commands,corresponding TUI commands are available.Solve−→Execute Commands...(a)Set the number of Deﬁned Commands to3.(b)Enable On option for all the commands.(c)Under Every,set7for all the commands.(d)Under When,set Time Step for all the commands.(e)For command-1,specify the Command as:display set-window1This command will make the window-1active.(f)For command-2,specify the Command as:display contour water vof01This command will display the contours of water volume fraction in the activewindow.(g)For command-1,specify the Command as:display hard-copy"vof-%t.tif"This command will save the image in the TIF format.The%t option gets replaced with the time step number,when the imageﬁleis saved.The TIFﬁles saved can then be used to create a movie.For theinformation on converting TIFﬁle to an animationﬁle,refer to/cfm/graphics01.htm(h)Click OK to accept the settings and close the panel.10.Set the surface monitors.Solve−→Monitors−→Surface...(a)Increase the number of Surface Monitors to1.(b)Enable Plot for monitor-1.(c)Under Every,select Time Step.(d)Click on Deﬁne...next to monitor-1.(e)Select Area Weighted Average in the Report Type drop-down list.(f)Select Grid and X-Coordinate in the Report of drop-down list.(g)Under Surfaces,select moving-wall.(h)Click OK to close both the panels.11.Save the case and dataﬁles(wave-init.cas.gz and wave-init.dat.gz).File−→Write−→Case&Data...Retain the default Write Binary Files option so that you can write a binaryﬁle.The .gz extension will save zippedﬁles on both,Windows and UNIX platforms.12.Start the calculation.Solve−→Iterate...(a)Set the Time Step Size as0.001s(b)Set Number of Time Steps to4000.(c)Click Iterate.Figure10.6:Scaled Residuals13.Save the case and dataﬁles(wave-4000.cas.gz and wave-4000.dat.gz).Figure10.7:Monitor Plot of Area Weighted Average on moving-wallStep10:Postprocessing1.Displayﬁlled contours of static pressure(Figure10.8).Display−→Contours...(a)Select Pressure...and Static Pressure in the Contours of drop-down lists.(b)Click Display.The pressure at the bottom of the tank is maximum and goes on decreasingtowards the top.This shows the variation of hydrostatic pressure due to theheight of the liquid.Figure10.8:Contours of Static PressureSummaryThe dynamic mesh model is used to apply periodic sinusoidal motion to the wall.This generates a wave in theﬂuid.The VOF model is used to track the air-water interface and consequently the wave motion.Non-iterative time advancement(NITA)was used to reduce the run time of transient simulation.Images displaying contours of water phase were captured to visualize the transient eﬀects.References1.Flow Around the Itsukushima Gate,an example from Fluent Inc.Marketing Cata-log,2003.Exercises/Discussions1.Run the simulation for longerﬂow time to check the wave pattern.2.Try running the simulation without non-iterative time advancement(NITA)option.(a)Are theﬂow patterns diﬀerent?(b)Compare the wall clock time taken to reach the sameﬂow time.3.Run the simulation using variable time step option.4.Try diﬀerent motions to the wall and observe wave patterns.This will need speciﬁc C compiler to create UDF library from the source code.5.What other situation can be simulated using the same meshﬁle?Links for Further Reading•http://www.prads2004.de/pdf/027.pdf•http://www.prads2004.de/pdf/138.pdf•http://www.math.rug.nl/∼veldman/preprints/OMAE2004-51084.pdf。

大涡模拟的fluent算例

Introduction:This tutorial demonstrates how to model the2D turbu-lentﬂow across a circular cylinder using LES(Large Eddy Simula-tion),and computeﬂow-induced noise(aero-noise)using FLUENT’s acoustics model.In this tutorial you will learn how to:•Perform2D Large Eddy Simulation(LES)•Set parameters for an aero-noise calculation•Save surface pressure data for an aero-noise calculation•Calculate aero-noise quantities•Postprocess an aero-noise solutionPrerequisites:This tutorial assumes that you are familiar with the menu structure in FLUENT,and that you have solved or read Tu-torial1.Some steps in the setup and solution procedure will not be shown explicitly.Problem Description:The problem considers turbulent airﬂow over a2D circular cylinder at a free stream velocity U of69.19m/s.The cylinder diameter D is1.9cm.The Reynolds number based on theﬂow parameters is about90000.The computational do-main(Figure3.0.1)extends5D upstream and20D downstream of the cylinder,and5D on both sides of it.If the computational domain is not taken wide enough on the downstream side,so that no reversedﬂow occurs,the accuracy of the aero-noise prediction may be aﬀected.The rule of thumb is to take at least20D on the downstream side of the obstacle.c Fluent Inc.June20,20023-1Aero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular Cylindernoise.msh.File−→Read−→Case...As FLUENT reads the gridﬁle,it will report its progress in the console window.2.Check the grid.Grid−→CheckFLUENT will perform various checks on the mesh and will report the progress in the console window.Pay particular attention to the reported minimum volume.Make sure this is a positive number.3.Scale the grid.Grid−→Scale...(a)Under Units Conversion,select cm in the Grid Was Created indrop-down list.(b)Click on Scale.4.Display the grid.Display−→Grid...(a)Display the grid with the default settings(Figure3.0.2).(b)Use the middle mouse button to zoom in on the image so youcan see the mesh near the cylinder(Figure3.0.3).Quadrilateral cells are used for this LES simulation becausethey generate less numerical diﬀusion than triangular cells.Cell size should also be small enough to make numerical dif-fusion much smaller than subgrid scale turbulence viscosity.Extra:You can use the right mouse button to check which zone number corresponds to each boundary.If you clickthe right mouse button on one of the boundaries in thegraphics window,its zone number,name,and type will beprinted in the FLUENT console window.This feature is c Fluent Inc.June20,20023-3Aero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular Cylindernoise1.cas/dat).File−→Write−→Case&data...You can skip items9-12to avoid the time-consuming calculationsnecessary to get the“dynamically steady state”ﬂowﬁeld.Instead,you can read the corresponding case and dataﬁles(cylnoise1.cas/dat).See Chapter28of the User’s Guide for more information on using3-14c Fluent Inc.June20,2002Aero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular Cylindernoise2.cas/dat).File−→Write−→Case&Data...Step7:Aero-Noise Calculation1.Save surface pressure variation data.(a)Set up the schemeﬁle and user-deﬁned functions(UDFs)foraero-noise calculation.i.Read the schemeﬁle,normally located in the lib directory,to create the Acoustic-Parameters panel.File−→Read−→Scheme...ii.Select acousticAero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular Cylindernoisenoise noisenoisenoise whole for the File Name to Read Surface Pressure.FLUENT’s aero-noise calculation module operates on asingleﬁle of surface pressure data at a time.If the surfacepressure data is saved in separateﬁles,you may want toconcatenate them into one singleﬁle.3-18c Fluent Inc.June20,2002Aero-Noise Prediction of Flow Across a Circular Cylinderacousticpowerpower db.xy for the File Name to Power Spectrum in dB Unit.(c)Changeﬁle name for the surface monitor.Solve−→Monitor−→Surface...i.Click on Deﬁne next to monitor-1ii.In the Deﬁne Surface Monitor panel,change the name of the monitor from monitor-point-behind-pres1-1.outto monitor-point-behind-pres4-1.out.(d)Save case and dataﬁles(cylnoise4.cas/dat).File−→Write−→Case&Data...(g)Exit FLUENTFile−→ExitIt is necessary to exit parallel FLUENT because the followingaero-noise calculation is performed with an Execute On De-mand UDF,which can only be used in the serial version ofthe solver.2.Calculate aero-noise(a)Start the serial version of FLUENT.c Fluent Inc.June20,20023-19Aero-Noise Prediction of Flow Across a Circular Cylinderpar.scm).File−→Read−→Scheme...(c)Read case and dataﬁles(cylnoise noise noise noise noise noisenoise whole.If you did not perform the calculation to write theﬁles thatwill be used in this step,you can continue by using the corre-spondingﬁles provided in the documentation CD.(e)Use the Execute On Demand UDF to perform the aero-noisecalculation.Deﬁne−→User-Deﬁned−→Execute On Demand...(f)Select the cal-sound UDF and click Execute.Note:There is a limit to the minimum number of time steps ac-cording to the sound calculation scheme.The minimum num-ber of time steps needs to be larger than n=T/dt,where Tis the propagation time through a distance L,roughly equalto the length scale of the sound generating wall,and dt is thetime step size applied in the unsteady calculation.If the givennumber of time steps for cal-sound is smaller than the requiredminimum number,a warning will be printed on FLUENT’sconsole window,along with the indication of the minimumnumber<n>of time steps requiredWarning:Number of Time Steps of The Input Surface Data Must be Larger Than:<n>.3-20c Fluent Inc.June20,2002Aero-Noise Prediction of Flow Across a Circular Cylinder1.69e+021.52e+021.35e+021.19e+021.02e+028.49e+016.80e+015.12e+013.43e+011.75e+016.49e-01Figure3.0.7:Velocity Vectors2.Display contours of static pressure at the current time step(Fig-ure3.0.8).Display−→Contours...3.Inspect the Sound Pressure Level(SPL)value.The the value ofsound intensity in units of W/m2and its alternative expression in dB are printed in the FLUENT console window after the execution of the cal-sound UDF,and areIntensity=4.060634e+00(W/m2)SPL=1.261719e+02(dB)c Fluent Inc.June20,20023-21Aero-Noise Prediction of Flow Across a Circular Cylinder3.91e+031.78e+03-3.56e+02-2.49e+03-4.62e+03-6.75e+03-8.89e+03-1.10e+04-1.32e+04-1.53e+04-1.74e+04Figure3.0.8:Static Pressure Contours4.Plot Acoustic Pressure variation(Figure3.0.9).Plot−→File...(a)Click on Add.(b)Select theﬁle cyl pres.xy and click OK.Remember to delete theﬁles you do not want to display from theFiles list.5.Plot Power Spectrum of sound pressure(Figure3.0.10).(a)Power Spectrum in units of P a2.Plot−→File...i.Click on Add.ii.Select theﬁle cyl spectrum.xy and click OK.Figure3.0.10shows a frequency range of0−2000Hz,withmajor and minor rules turned on.From thisﬁgure it can be 3-22c Fluent Inc.June20,2002Aero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular Cylinderpower db.xy and click OK .Frequency (Hz)5.00e+016.00e+017.00e+018.00e+019.00e+011.00e+021.10e+021.20e+0201e+032e+033e+034e+035e+036e+037e+038e+039e+031e+04Power Spectrum (dB)Figure 3.0.11:Plot of Power Spectrum of Sound Pressure.Figure 3.0.11shows a frequency range of 0−10kHz .6.Inspect Surface Dipole Strength.(a)Display contours of Surface Dipole Strength on surface cylin-der (Figure 3.0.12).Display −→Contours...i.In the Contours Of drop-down lists,select User-DeﬁnedMemory and udm-0.ii.Turn oﬀNode Values .3-24cFluent Inc.June 20,2002Aero-Noise Prediction of Flow Across a Circular Cylinder4.13e+053.72e+053.31e+052.89e+052.48e+052.07e+051.65e+051.24e+058.25e+044.12e+04-1.94e+02Figure3.0.12:Contour of Surface Dipole Strengthiii.Click on Display.The value of Surface Dipole Strength for each cell face is storedfor the center of the face on the cylinder wall.Surface DipoleStrength is the distribution of unit area contribution on thesound generating surface to the intensity of sound measuredat the observer’s location.(b)Plot Surface Dipole Strength(udm-0)on surface cylinder(Fig-ure3.0.13).Plot−→XY Plot...Figure3.0.13shows Surface Dipole Strength distribution onboth the upper and lower half cylinder faces.Extra:Once theﬂow simulation reaches a“dynamically steady state”, the accuracy for predicting Sound Pressure Level(SPL)and Power Spectrum is usually dependent on the number of time steps used.LES requires a mesh size as small as the length scale of eddies in the inertial sub-range.The corresponding time step size is calcu-c Fluent Inc.June20,20023-25Aero-Noise Prediction of Flow Across a Circular CylindercylinderFigure3.0.13:Plot of Surface Dipole Strengthlated by dt=Cdx/U,where C is the Courant number,and thus isvery small compared with the period T of the dominating acousticwave component(i.e.that corresponding to the frequency of thehighest peak in the power spectrum).For an accurate aero-noiseprediction,at least10periods of the dominating wave componentare required for sampling.The number of time steps for this re-quirement can be roughly estimated for theﬂow over the cylinder.In a certain Reynolds number range(roughly Re<50000),theStrouhal number(St=fD/U)for the dominating frequency f isabout0.2.Therefore,the period is T=D/0.2/U.From the aboveequations,the number of time steps for each period can be calcu-lated as N=T/dt=5/CD/dx.In LES,the ratio between thedomain scale D and the typical cell size dx can easily be50-100.As an example,if C is taken as order of1,N can be as high as250-500for each period.For40periods,10000-20000time stepsmay be required.Summary:This tutorial demonstrated how to set up and calculate an aero-noise problem for theﬂow around a cylinder,using the2D LES 3-26c Fluent Inc.June20,2002Aero-Noise Prediction of Flow Across a Circular CylinderAero-Noise Prediction of Flow Across a Circular Cylinder。

Fluent二维流体动画实例两种方法

二维流体动画实例软件版本Fluent-6.3.26.Gambit-2.2.30.具体步骤1. 在Fluent中导入已经定义好的各种参数条件的cas文件开启Fluent，选择2ddp，在Fluent中，“File” —“Read”—“Case&Data”，选择文件夹“Fluent-File”中的“mix-data.cas”文件。

这个二维模型的制作过程在PDF中有说明，上面的文件是已经做好的模型。

2. 初始化数据在Fluent中，“Solve”—“Initialize”—“Initialize”，点击“Init”，初始化完后点击“Close”关闭对话框，如图1所示。

图1 初始化数据3. 定义动画在Fluent中，“Solve”—“Animate”—“Define”，弹出Solution Animation对话框，如图2所示的设置。

图2 动画设置对话框接下来点击图2对话框中的“Define”，弹出Animation Sequence对话框，在“Storage Type”中选择“PPM Image”，在“Storage Directory”中设置动画序列的保存路径，注意路径不得有中文，在“Display Type”中选择“Contours”，弹出Contours对话框，按自己的显示需要设置好点击或直接点击“Display”弹出显示窗口，再点击“Close”完成等值线的设置，想要更改Display Type的话则点击“Properties”即可，分别如图3~5所示。

图3 动画序列对话框设置图4 显示窗口图5 等值线设置设置完成后，在Animation Sequence对话框中点击OK完成设置，再在“Solution Animation”对话框中点击OK完成设置。

4. 进行迭代运算“Solve”—“Iterate”，弹出迭代运算对话框，迭代20次，如图6所示，迭代过程中，每迭代一次，会保存一帧动画到之前设定的保存路径中。

Fluent模型使用技巧

Fluent模型使⽤技巧1.多相流动模式我们可以根据下⾯的原则对多相流分成四类：⽓-液或者液-液两相流：o⽓泡流动：连续流体中的⽓泡或者液泡。

o液滴流动：连续⽓体中的离散流体液滴。

o活塞流动:在连续流体中的⼤的⽓泡o分层⾃由⾯流动：由明显的分界⾯隔开的⾮混合流体流动。

⽓-固两相流：o充满粒⼦的流动：连续⽓体流动中有离散的固体粒⼦。

o⽓动输运：流动模式依赖诸如固体载荷、雷诺数和粒⼦属性等因素。

最典型的模式有沙⼦的流动，泥浆流，填充床，以及各向同性流。

o流化床：由⼀个盛有粒⼦的竖直圆筒构成，⽓体从⼀个分散器导⼊筒内。

从床底不断充⼊的⽓体使得颗粒得以悬浮。

改变⽓体的流量，就会有⽓泡不断的出现并穿过整个容器，从⽽使得颗粒在床内得到充分混合。

液-固两相流o泥浆流：流体中的颗粒输运。

液-固两相流的基本特征不同于液体中固体颗粒的流动。

在泥浆流中，Stokes数通常⼩于1。

当Stokes数⼤于1时，流动成为流化（fluidization）了的液-固流动。

o⽔⼒运输:在连续流体中密布着固体颗粒o沉降运动:在有⼀定⾼度的成有液体的容器内，初始时刻均匀散布着颗粒物质。

随后，流体将会分层，在容器底部因为颗粒的不断沉降并堆积形成了淤积层，在顶部出现了澄清层，⾥⾯没有颗粒物质，在中间则是沉降层，那⾥的粒⼦仍然在沉降。

在澄清层和沉降层中间，是⼀个清晰可辨的交界⾯。

三相流(上⾯各种情况的组合)各流动模式对应的例⼦如下：⽓泡流例⼦：抽吸，通风，空⽓泵，⽓⽳，蒸发，浮选，洗刷液滴流例⼦：抽吸，喷雾，燃烧室，低温泵，⼲燥机，蒸发，⽓冷，刷洗?活塞流例⼦：管道或容器内有⼤尺度⽓泡的流动分层⾃由⾯流动例⼦：分离器中的晃动，核反应装置中的沸腾和冷凝粒⼦负载流动例⼦：旋风分离器，空⽓分类器，洗尘器，环境尘埃流动风⼒输运例⼦：⽔泥、⾕粒和⾦属粉末的输运流化床例⼦：流化床反应器，循环流化床泥浆流例⼦:泥浆输运，矿物处理⽔⼒输运例⼦：矿物处理，⽣物医学及物理化学中的流体系统沉降例⼦：矿物处理2.多相流模型FLUENT中描述两相流的两种⽅法:欧拉⼀欧拉法和欧拉⼀拉格朗⽇法，后⾯分别简称欧拉法和拉格朗⽇法。

二维离心泵流动模拟上机指导书(fluent)

二维离心泵的数值模拟与性能预测一、实验目的熟悉和掌握CFD数值模拟的基本方法，能够独立进行简单二维水力模型的CFD数值模拟。

二、研究对象研究如图所示的二维离心泵，该泵由旋转的叶轮和静止的蜗壳两部分构成。

流体从叶轮中央的圆形进口沿径向均匀进入叶轮，经过旋转的叶片作用后，得到能量，从蜗壳出口排出。

已知叶轮的叶片数为6，叶轮进、出口直径分别为120mm和220mm，叶片进口安放角（叶片与圆周方向夹角）和出口安放角分别（叶轮中心至蜗壳螺旋线起点为20 和25 ，叶片厚度为3mm。

蜗壳隔舌角的连线与水平夹角）为35 ，出口段扩散角为8 。

图表1 二维离心泵示意图图表2 UG NX所绘二维离心泵三、计算步骤1、利用Gambit 对计算区域离散化和指定边界条件类型步骤1：导入几何模型生成几何模型的方式有许多种，如Autocad，Pro/E，UG NX等，Gambit也自带简单的绘图功能，在这里UG NX绘图。

如下图，我们将会给出绘图文件。

在UG NX绘完图后，需将结果导出以便Gambit使用，这里导出为Parasolid，生成后缀名为x_t的文件。

主要内容：在Gambit中选择File/Import/Parasolid命令，选取先前生成的文件11.x_t，则二维离心泵模型被装入到Gambit。

结果如图：图表 3 导入到Gambit的二维离心泵几何模型步骤2：网格划分为了对几何区域划分网格，单击Operation / Mesh / Face / Mesh Face按钮，弹出如图所示的Mesh Faces对话框。

在Faces列表框中选取蜗壳区域，在Elements 列表框中选择Tri(三角形单元)，在Type列表框中选拌Pave(非结构网格)，选中Scheme命令组中的Apply复选框，然后，从Spacing区域的列表框中选择Interval Size(指定网格间隔)，在文本框中输入10，选中该区域中的Apply复选框，最后选中Options区域中的Mesh复选框，单击Apply按钮，则生成蜗壳内流体区域的网格。

Fluent模拟的基本步骤PDF.pdf

Fluent模拟的基本步骤1.运行Fluent 出现选择Fluent version选择界面一般二维问题就选择默认的2d，即单精度二维版本就可以了，但是本问题求解区域是一个扁长形状的，建议选择2ddp，即二维双精度版本，计算效果更好。

2.打开网格文件从菜单file→Read→Case→选择fin目录下的fin.msh文件3.指定计算区域的实际尺寸在Gambit建立区域时没有尺寸的单位，此时应该进行确定，也可以对区域进行放大或缩小等。

在菜单Grid下选择Scale出现上面的对话框。

将其中的Grid was created by 中的单位m，更改为mm，此时scale factor X和Y都出现0.001。

然后按Scale4.选择模型该问题是稳态问题，在Solver 中已经是默认，只是求解温度场。

由菜单Define →Models→Energy然后选择Energy Equation。

5.指定边界条件和求解区域的材料需要将求解区域的四个边界进行说明，由菜单单Define →Models →Boundary conditions。

首先设置左边界，即肋根的条件。

点击left项，Type 列表中缺省指定在Wall，所以不需要改变，再点击Set选择thermal conditions列表中的Temperature，并且在右侧Temperature(k)中填入323（即50℃），然后点击OK完成。

按照同样方法对up、down和right 三个边界进行设置。

这三个边界均为对流边界，需要给出表面传热系数和流体温度。

本问题的求解区域为固体，并且设定其物性参数。

在zone 列表中选择zone(在Gambit 中指定的名字)，已经是默认的solid.点击set点击Edit编辑材料的物性，本问题只是设计材料的导热系数，所以仅需将导热系数的值更改为160，然后点击Change后再close，上一个页面后按ok。

此时可关闭Boundary conditions。

[VIP专享]史上Fluent最详细操作步骤一看就懂

Fluent简单分析教程第1步双击运行Fluent，首先出现如下界面，对于二维模型我们可以选择2d（单精度）或2ddp（双精度）进行模拟，通常选择2d即可。

Mode选择缺省的Full Simulation即可。

点击“Run”。

然后进入如下图示意界面：第2步：与网格相关的操作1.读入网格文件car1.mesh操作如下图所示：打开的“Select File”对话框如图所示：（1）找到网格文件E:\gfiles\car1.mesh;（2）点击OK，完成输入网格文件的操作。

注意：FLUENT读入网格文件的同时，会在信息反馈窗口显示如下信息：其中包括节点数7590等，最后的Done表示读入网格文件成功。

2.网格检查：操作如下图所示：FLUENT在信息反馈窗口显示如下信息：注意：（1）网格检查列出了X,Y的最小和最大值；（2）网格检查还将报告出网格的其他特性，比如单元的最大体积和最小体积、最大面积和最小面积等；（3）网格检查还会报告出有关网格的任何错误，特别是要求确保最小体积不能是负值，否则FLUENT无法进行计算。

3.平滑（和交换）网格这一步是为确保网格质量的操作。

操作：→Smooth/Swap...打开“Smooth/Swap Grid”对话框如图所示：（1）点击Smooth按钮，再点击Swap，重复上述操作，直到FLUENT报告没有需要交换的面为止。

如图所示：（2）点击Close按钮关闭对话框。

注意：这一功能对于三角形单元来说尤为重要。

4.确定长度单位操作如下图所示：打开“Scale Grid”对话框如图所示：（1）在单位转换（Units Conversion）栏中的（Grid Was Created In）网格长度单位右侧下拉列表中选择m；（2）看区域的范围是否正确，如果不正确，可以在Scale Factors 的X和Y中分别输入值10，然后点击“Scale”或“Unscale”即可；（3）点击Scale；（4）点击Close关闭对话框。

fluent 二维大涡模拟命令