Flotherm教程2Build,SolveandAnalyseasamplecase

Vents
Model with perforated plates
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Save / Load
Before building, save project
– Project / Save – Choose solution directory – Enter project name
Attribute Attach Ambient to
System
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Solving
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The governing equations are solved iteratively
Error in system is measured
activate Source Menu Select Location Alternatively, size and location can be set in DB
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Adding Power
Select Source Right-Click to
reposition
Move object
Re-size in one direction
Re-size in two directions
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Attaching Material
Open Library Manager Select Material Drag it onto Enclosure Or: Right-Click on
For a thermal source, choose Applies To: Temperature
Set the Power
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How do I add vents?
Select appropriate item (Perforated Plate SP)
The equations are solved at each cell
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Define Grid
Why do we need grid?
Allows equations to be solved at discrete points
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Define what to model
Start Simple
Electronics Box
Chassis
Model with an enclosure
Components
Model with a heat source
Set its size Position it correctly Define the power
(Source Attribute)
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Setting Size & Location
Select Source Right-Click to
When this error is low enough, results can be accepted
Select Location Type appropriate
position
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Setting Size & Location
Alternatively, size and location can be set in DB
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Define Grid
How do we add grid? Geometry provides keypoints for grid
Grid lines automatically appear along edges of all objects
Setting Size
Select Enclosure Right-Click to activate
Enclosure Menu Select Construction Type appropriate size Type appropriate thickness Walls can be thin (collapsed)
– Select Material – Select the attached
material from list – Click Edit
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How do I add heat?
Select appropriate item (Source)
Attach ambients to describe conditions outside the domain
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Ambient Conditions
Right-Click on the System Node
Select Ambients Create Ambient
Select appropriate item
Set its size Position it correctly Define the material
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Chassis Structure
To model a hollow box, use the Enclosure SmartPart
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Setting Loss Coefficient
The pressure drop characteristics of the Perforated Plate are set in the Construction Dialog
or thick (non-collapsed)
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Setting Location
Select Enclosure Right-Click to activate
Enclosure Menu Select Location Type appropriate location
Select Enclosure from the PM geometry palette – default enclosure is created
Select Enclosure in the DB geometry palette – now draw the enclosure
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Set its size Position it correctly Define the loss
coefficient
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Setting Size
Select Perforated Plate
Right-Click to activate Perforated Plate Menu
To load existing project
– Project / Load – Choose solution directory – Select project from list
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How do I create geometry?
activate Source Menu Select Source Create New Source Attach Source from List
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Adding Power
Source Power is controlled by the Source Attribute
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Define Grid
How do we add grid?
Grid can be generated automatically to four default levels
N.B. NoFra Baidu biblioteke = Keypoint grid
Enter a hole pattern Or enter a free area ratio Choose Resistance Model
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Define Grid
What is grid?
The solution domain is split into a number of finite volumes
Select the Perforated Plate Move handles to resize Move Perforated Plate to
reposition
Move object
Re-size in one direction
Re-size in two directions
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Enclosure Select Material Attach Material from
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Attaching Material
To view Material properties
– Right-Click on Enclosure
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Define Grid
How do we add grid?
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Solving
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Governing equations are solved within domain
Select Construction Type appropriate
size
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Setting Location
Select Perforated Plate
Right-Click to activate Perforated Plate Menu
More grid = more points to capture overall picture = more precise results
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Refining Grid
Why do we need grid?
As we refine the grid, more detail is apparent
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Setting Size & Location
Alternatively, size and location can be set in DB
Select the Enclosure Move handles to resize Move Enclosure to
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Lecture 2A
Build, Solve and Analyse a Simple Case
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Five steps to build a model
Step 1 – Define what to model Step 2 – Create geometry Step 3 – Add grid Step 4 – Solve the model Step 5 – Analyse the results