[johny_walker]

Hello,

I have attached pictures showing my grid. I am performing a 2D vehicle aerodynamic simulation with a moving ground on a windsor model. I have troubles in meshing boundary layers between the vehicle floor and moving ground. The ground clearance is 0.05m.

I am using triangular unstructured meshing strategy. For the inflation layer, i am using y+ = 1 at vehicle surface and y+=30 at moving ground. I have kept inflation layers to be 35 at vehicle surface and 14 at moving ground. I am also using first thickness way of creating BL. I have used 'stair stepping' option in mesh.

In the picture named 'Bottom' in PDF, there is this region (marked in blue) that gets formed when I insert BL at ground. When I suppress the BL on ground, this region goes away. Will this region pose a problem? I have tried refining it and tried all possible ways to remove it that I was aware of, but it only goes when the ground BL is suppressed. Increasing/decreasing the BL doesnt work, increasing the ground clearance doesnt work.

In the picture named 'Domain', the edge of the region marked with blue can be made coincident with vehicles trailing edge and it makes the region (marked in the picture named ‘bottom’) goes away but then it squeezes the BL at the rear bottom corner and no matter how much I refine it, BL at that corner is not proper.


Any help shall be appreciated.


Regards

[Svetlana]

In domain.jpg there is a line which intersects the vehicle bottom in the problematic point. What is it for?

[johny_walker]

That is the subdomain. So the entire domain is divided into subdomains and then these subdomains are face meshed.

[Svetlana]

You may have applied different inflation settings or different sizing controls for different subdomains..? This is why the problem shown in Bottom.jpg (1/5) would occur.

If it is confusing, please post screenshots of all local mesh sizing controls.