Learning Forum

[Vishal95]

I want to define convection boundary condition on the right boundary of the 2D surface. If I select the right boundary with edge select filter, I do not see convection boundary condition option. If I highlight steady state thermal on outline, convection bc appears but I'm not able to select the edge. Instead it selects either face or body. I have attached screenshots of the issue. I'm following Cornell University's course on engineering simulation. I'm not sure where the problem is.

 

[Karthik R]

Hello,

Do you see a question mark in your structure tree? It is because your default problem settings is set to 3D and you have imported a 2D plane into steady state thermal. This confuses the solver because all boundary conditions are applied on surfaces (not on lines) and as soon as you click on convection to select the appropriate boundary, Steady state thermal defaults to the face filter (instead of line because the solver is expecting to solve a 3D problem).

The way to fix this is the set the 'Analysis type' from 3D to 2D. You can do this in WorkBench. Right-click on geometry and open 'Properties'. Here is a screenshot of what it would look like.

I hope this helps.

Best Regards,

Karthik

[peteroznewman]

Hello Vishal,

If I recall correctly, you will not be allowed to change to 2D after you have built the model in 3D.
You will have to start over and set the Geometry property to 2D before you start building the Model.

Regards,
Peter

[Vishal95]

Hello Peter,

Yes, I was not allowed to change to 2D. I started from scratch again.

Regards,

Vishal

[neelima335]

Hello,

Do you see a question mark in your structure tree? It is because your default problem settings is set to 3D and you have imported a 2D plane into steady state thermal. This confuses the solver because all boundary conditions are applied on surfaces (not on lines) and as soon as you click on convection to select the appropriate boundary, Steady state thermal defaults to the face filter (instead of line because the solver is expecting to solve a 3D problem).

The way to fix this is the set the 'Analysis type' from 3D to 2D. You can do this in WorkBench. Right-click on geometry and open 'Properties'. Here is a screenshot of what it would look like.

I hope this helps.

Best Regards,

Karthik

 

Hello kremella

I also designed a model in 2D by keeping analysis type as 2D. but when I'm meshing it is changing to 3D. This problem disappeared when I changed analysis type to 3D, but the question mark is appearing in tree outline beside geometry.

Could you please suggest me what is wrong with the model.

This image is 2D model with analysis type as 2D before meshing.

This is 2D analysis after meshing - It can be seen that model is extruded.

This is the same model with analysis type 3D in geometry. It did not extrude after meshing, but question mark appeared beside geometry.

[peteroznewman]

The 2D analysis assumes a unit depth, and it displays that. Why is that a problem?

When you have a 3D analysis with a surface, you assign that surface a thickness. It is possible to display that thickness if you turn on Thick Shells and Beams as a display setting.

 

[Devanshi109]

Hello,

I am doing a 2D heat sink analysis. I did chose the 2D option before building my model. But when I solve, the geometry explodes into 3D.

 

Could you please suggest a solution.

Thank you.