Learning Forum

[nagarajan.dharanibalan]

Dear Team, I'm trying to simulate exhaust manifold which means the thermal source is exhaust gas, structural part is manifold and structural load is mounting bolts. I have attached two screen shots showing, 1. Exiting workflow like flow - structural - results 2. New workflow, there is no option to connect thermal after structural since I want to do combined simulation of flow, structural and thermal. Expected end result is stress and temperature distribution based both structural and thermal loads Actually I'm unable to add thermal physics after structural. If it is not possible. How I can give structural inputs for thermal evaluation on the same model which includes the flow.

[Gaurav Sharma]

Hi Nagarajan D

There doesn't seem to be a need to add thermal physics after structural, considering that you are working with a manifold. Generally for such applications, pressure from fluid and temperature distribution from thermal are provided as inputs to structural analysis.

This can be done by, using the Fluid-Solid Heat Transfer template of Discovery AIM

Please make sure to select both options under additional physics in order to incorporate thermal as well pressure effects in structural analysis.

 

The solver will first solve the flow part for pressure and temperature distributions and these will then be used as imported values to structural analysis and the workflow will look like this:

 

Though there is no separate thermal tab, but all required thermal inputs can be provided using "Solid Thermal conditions" under Flow tab itself. Also, the temperature distribution will be available under Flow results.

 

I hope this answers your query. 

Thanks & Regards,

Gaurav

[nagarajan.dharanibalan]

Thanks for your reply.

If I'm adding thermal conditions in "Flow Tab", I'm able to define convection conditions along with temperature.

Gas temperature is already defined in flow conditions. Is this conditions are fine?

 

When we come to work flow, it is generating two loops in parallel 

1. From meshing -> Structural -> Results

2. From meshing -> Flow -> Results

Which work flow I have to consider if I'm expecting results which includes effect of both thermal behavior due to structural loads. Like material expansion, max. strain and stress points.

Regards

Nagarajan D

[Gaurav Sharma]

Nagarajan D 

Yes the gas temperature defined under flow condtions, will be taken into account while calculating temperatures of the solid zone.

I hope the workflow with mesh tab looks like:

 

This is fine as long s the output of "Flow" tab is shared as an input to "Structural" tab.

Regards,

Gaurav

[nagarajan.dharanibalan]

Gaurav_ANSYS

hi

please refer below screen shots. Where in work flow loop,  starts from Geometry -> Mesh -> Flow -> Structural -> Results, In results I have created new contour in that I can't able to add temperature distribution.

Based on previous comment on gas temperature will be taken into account.

So where I can get the temperature distribution contour will be available in results module

Regards

Nagarajan D

[Gaurav Sharma]

Nagarajan D 

Temperature plots are available under Flow results here:

 

Regards,

Gaurav

[nagarajan.dharanibalan]

Thanks.

Dear Gaurav_ANSYS

on the same model, I'm unable get plot for plastic strain in this model on results.

showing some errors refer attached screen shot.

Could you explain how to add in physics and where the options are available?

Regards

Nagarajan D

[Gaurav Sharma]

Nagarajan D 

This is possibly because you are solving an elastic problem and not an elasto-plastic one.

In order to account for plasticity, it is important for the material defined to have bilinear isotropic hardening property specified. However, this is not enough, and we also need to switch ON plasticity by selecting the plasticity model to be used under Material assignment settings as shown below. By default this option is set to "none".

 

Here is a video tutorial that talks about defining a plasticity problem end to end. Hope you find it useful

Please let me know if the suggestion is helpful or in case the problem still remains.

Regards,

Gaurav

[nagarajan.dharanibalan]

Gaurav_ANSYS 

I tried that but I can't able to update the same. Please refer attached screen shot.

Stating that we have to select different material.

Regards

Nagarajan D

[Gaurav Sharma]

Nagarajan D 

I encourage you to please refer the Knowledge article I shared in my last post as that will help you around with most of the elemental problem you may encounter while setting up a plasticity model.

Unlike structural steel, cast iron is not known to undergo plastic deformation. Hence, the default cast iron material in AIM library does not have Bilinear Isotropic Hardening definition added to it. However, if for some reason you want to incorporate it, you can manually add the same and provide required material inputs.

Attached below is the properties of default structural steel and "Bilinear Isotropic Hardening" can be seen here, but if we go to cast iron, this property is not available by default:

 

Thanks & Regards,

Gaurav