Learning Forum

[PRAJVAL PRASAD INAMDAR]

I am performing thermomechanical fatigue analysis of exhaust manifold. For that I want to run the fluid simulation for bigger time step so that a steady state temperature is achieved for that time step. Then I want to give that temp profile to thermal model having less time step to get the thermal stresses induced. Can I do this in ansys ? Ani if yes how should I proceed? Also can I add temperature dependent properties of material as at high temperatures of exhaust the properties change drastically? Please help. I shall be obliged.

Thanks in advance.

[RM]

Hi,

Is it a 1-way or 2-way analysis?

Time Step Size and Number of Time Steps for fluent are controlled by system coupling, so the values specified in fluent are ignored. 

If it is 2-way, refer 42.5. System Coupling Related Settings in Fluent (ansys.com) and System Coupling Related Settings in Mechanical (ansys.com) for settings required as inputs in both participants.

[PRAJVAL PRASAD INAMDAR]

It's a 2 way fsi. I was to make the fluent come to steady state and then transfer that data to thermal. I want have time step of fluent to be less  than thermal (say 0.001 fluent and 0.01 for thermal) and I want to couple them. Basically I want that after some iterations of fluent then only thermal should start calculation.

Thanks.

 

[RM]

Hi 
You might want to refer to Steady-Transient analysis Transient Analysis Type (ansys.com)

In such steady-transient analyses, System Coupling will show the overall analysis type as Transient, while the physics with the shorter/faster timescale is solved as steady-state.

[Eden Wheeler]

Yes, you can perform the thermomechanical fatigue analysis of an exhaust manifold in ANSYS. To achieve a steady-state temperature profile for a larger time step, you can run a fluid simulation using a transient solver until the temperature stabilizes. Once you have the steady-state temperature profile, you can export it and import it into a thermal model with a smaller time step.You can also check this: aws certified developer course

To proceed, follow these steps:

1. Set up and solve the fluid simulation using a transient solver in ANSYS Fluent or a similar tool.
2. Monitor the temperature until it reaches a steady-state condition.
3. Export the temperature profile from the fluid simulation at the desired time step.
4. Set up a thermal analysis in ANSYS Mechanical or a similar tool, using the imported temperature profile as a boundary condition.
5. Run the thermal analysis with a smaller time step to obtain the thermal stresses induced in the exhaust manifold.