Ahmed Body Drag Validation Problem

[Get_Barried]

Hi @LWhitson2,

Just to add my 2 cents.

@LWhitson2

find it hard to believe that we need a nearly 40M cell grid to calculate the drag coefficient on an Ahmed Body to a reasonable accuracy when I can find peer reviewed literature using much smaller grids. Below are two references where the authors completed LES/RANS computations using grids on the order of 5M cells that matched well with experiments:

Mesh size or number of cells is not a direct one to one comparison for mesh quality. There are a multitude of things to consider that comes into mesh quality. It is very likely that the grids on the papers have been very well generated with very tight control and are well optimized. It is totally possible to do this on SimScale and with snappyhexmesh but you will need ALOT of time to fine tune all the parameters to get the quality you need while optimizing the number of cells. As Darren has mentioned, y+ is also a big part of it and it contributes greatly to your mesh count/quality.

Alot more work needs to be done on the meshing end.

Cheers.

Regards,
Barry