diverging issue of sst in supersonic flow

LunarKing1110 · December 11, 2023, 08:27

Hi all,
I am a new user and have an issue with the supersonic simulation of SWBLI using sst model, it always diverges with about 50 iterations. Can someone help take a look at my cfg file? I attach it with the thread. Thanks a lot!

bigfootedrockmidget · December 11, 2023, 10:50

You have changed many things in the config file. Did you try to run the original V&V testcase with the original geometry?

I see that you have also changed the reference length, so you are running this on another geometry as well. It is therefore very difficult to assess where the problem lies if you do not provide the mesh that you are using.

LunarKing1110 · December 11, 2023, 11:21

hi,
yes I have tested the V&V before and it works. For my case, the mach number is higher, but the geometry is quite similar to the V&V. Can you get access to my geo file (i also use Gmsh) and help me debug with this diverging issue? Thanks a lot!

LunarKing1110 · December 11, 2023, 11:31

Hi,
I just really struggled with the issue. I will be really APPRECIATED if you can help me take a look to it. A lot of thanks again!

bigfootedrockmidget · December 11, 2023, 17:58

Just go back to the original configuration file and use those settings. Also make sure to check an intermediate result in e.g. paraview to see if there are some local problems in the mesh. You need for instance quite small meshes at the wall to get y^+ close to 1.

You can also first set CFL_ADAPT=NO and set CFL=1.

December 11, 2023, 17:58		#5
bigfootedrockmidget Senior Member bigfoot Join Date: Dec 2011 Location: Netherlands Posts: 676 Rep Power: 21	Just go back to the original configuration file and use those settings. Also make sure to check an intermediate result in e.g. paraview to see if there are some local problems in the mesh. You need for instance quite small meshes at the wall to get y^+ close to 1. You can also first set CFL_ADAPT=NO and set CFL=1. giovanni.medici likes this.

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December 11, 2023, 10:50		#2
bigfootedrockmidget Senior Member bigfoot Join Date: Dec 2011 Location: Netherlands Posts: 676 Rep Power: 21	You have changed many things in the config file. Did you try to run the original V&V testcase with the original geometry? I see that you have also changed the reference length, so you are running this on another geometry as well. It is therefore very difficult to assess where the problem lies if you do not provide the mesh that you are using.

December 11, 2023, 11:31		#4
LunarKing1110 New Member Shukai Wang Join Date: Nov 2023 Posts: 10 Rep Power: 3	Hi, I just really struggled with the issue. I will be really APPRECIATED if you can help me take a look to it. A lot of thanks again!