Error in Transient thermal analysis in Ansys 1

[Meherrahul]

Hello Everyone,

I am using transient thermal analysis in ansys and getting the following error -

Details of the simulation are as follows -
Time = 750 sec
Number of steps = 3
Mesh size = 280000
Boundary conditions include convection, radiation and heat flux.

Is anybody familiar with the above error and can suggest some solution ? Thanks in advance for help.

 

[NRP99]

This error is related to parallel processor/using distributed Ansys. Did you change any settings in the number of processors of remote solve or any other settings? Also other reasons for the getting this error might be limitations of hardware, software and some analysis types are not supported with specific settings. Refer "ANSYS Mechanical APDL Parallel Processing Guide" for more details.

Your analysis can run with default settings.

 

[Meherrahul]

Thanks NRP99 for your response.

I have kept the default settings in Ansys. When I run the simulation while suppressing the radiation, it is running without any error.
I will refer the parallel processing guide.

 

[NRP99]

What is you machine configuration? For default settings most of the analysis works without any error unless you have model size big/element and node count is high enough causing memory requirement to shoot up than available. What are other errors when you use radiation?

 

[Meherrahul]

My machine configuration -

Processor Intel(R) Core(TM) i7-7820X CPU @ 3.60GHz 3.60 GHz
Installed RAM 32.0 GB (31.7 GB usable)

The total number of elements are around 280000 which is quite normal for this machine.

I got a suggestion from someone to run this analysis by unchecking the "distributed memory" checkbox. But then I got the following error - "Some of RDSF faces have not had the RSURF command applied to them".

 

[NRP99]

Could you post pictures of the analysis model? Is this the only error? It is not possible or helpful to suggest anything without looking at model.

May be you have re-meshed the surfaces where you have applied the RDSF which after re-meshing, the RDSF enforcement has gone. But I am not sure about this since not done any radiation analysis. Check "Thermal analysis guide" for more information.

 

[Meherrahul]

Thanks NRP99 for your suggestions. Actually I am not at liberty to share the information of the analysis as the geometry of the structure is confidential for my company.

I could not figure out the reason for the error. But I found an alternative for doing the analysis without that error. Earlier, there were 3 steps in my analysis with different boundary conditions for each of them. So instead of doing a multistep analysis, I created 3 different analysis where the initial temp of 2nd and 3rd analysis were taken as the final temp of the 1st and 2nd analysis respectively. This can be done in workbench by right clicking on "solution" of the transient thermal module and selecting "transfer data to new" > "Transient thermal".