Unphysical solution field around geometry primitives

[sitthichats]

Hi,

I have been conducting simulations to find drag on an underwater vehicle. I have found that the solution fields eg pressure field has an abnormal result. The flow goes in the - y direction. Figures below show the model and the pressure field. The red arrows identify the wedge-like pressure contour.

As shown, the pressure contour is in a peculiar shape, as if there was some sort of box-shaped boundaries obstructing the flow. The approximate shape of the hypothetical boundaries coincides with the geometry primitives as shown below.

I suspect that there is something wrong with the geometry primitives? I have done CFD simulations numerous times but this is the first time I encountered this problem

Link to my project: SimScale

Any help would be greatly appreciated

Boris

[tsite]

Hi Boris, thank you for using the forum! This issue seems to be related to the mesh in that area.
Try using the Standard mesher instead of the Hex dominant, as shown here. Aerodynamic Flow Behavior Around a Vehicle Tutorial | SimScale
The transition between the region refinements should be done smoothly if you use appropriate refinement settings like in the page I sent you.
Let me know how it goes!

Best regards,
Fillia