Learning Forum

[SpeedyG]

Hey all,

i'm running a coupled-field transient (structural/thermal) simulation in Ansys Mechanical Workbench. The model consists of two discs that rotate in relation to each other. The one disk is given a rotation and additionally a pressure is applied. Heat is thus generated in the frictional contact.

I have run the simulation and it has been completed. However, the results show temperatures that are below the ambient temperature (80°C). Has anyone ever encountered a similar problem or has an idea for a solution?

If any more model details are needed, please just let me know.

[ErKo]

Your initial conditions (Initial temperature value) in Initial Physics Option (see image below) are probably set to below your 80 degrees - so if you part starts from 80 degrees then you need an initial condition (Initial temperature value) of 80 and not 22 which is the default.
All the best

Erik

[SpeedyG]

thanks for your answer. Unfortunately, this is not the case. My initial temperature is 80┬░C (see picture).

[ErKo]

Hi
What are the BC on that face (show details e.g., ambient temp there) and why do you have a command snippet.
Erik

[SpeedyG]

Hi Erik that face has no BC. It is only defined as an asymmetric frictional contact face. The target face is on the 1. Disc (see image from first post).
The command snippet only contains the following command: NEQIT,140 (to increase the number of iterations).
I will post some images so you can get an overview of all the boundary conditions.

[ErKo]

Hi Can you also show the temperature graph of a node on that edge that has a low temp. (say 55 degrees) to see how it evolves during the entire simulation.
Erik

[SpeedyG]

Sure, the following image contains the temperature graph of the Node 5644 (see above).

[ErKo]

Hi
I can see that it starts at 80 which is good, but then it goes down which is less good.

So this could be an undershoot problem with higher order elements.

Try this :
Mesh with linear elements - set it in the Mechanical User INterface, under Mesh settings/Element order -> Linear.
All the best

Erik