[StudentIB]

Hi,

I'm analyzing a simple test case of a plate subjected to airflow and trying to obtain a good agreement with an analytical solution of the pressure acting on the plate (the next step is deformation calculation but for that, I need an accurate pressure value). Of course, I assume uniform pressure distribution calculated simply as drag force divided by area. I use this basic formula for drag force: F_D=0.5*rho*C_D*U^2*A where C_D=1.28 (I've found this value for plates, but I'm not sure if it's accurate enough) and A is simply the area of the rectangular surface facing the flow (width of the plate times its height).

The simulation is steady-state, laminar with inlet (2 m/s) and outlet (0 Pa) boundary conditions. I also applied a no-slip wall boundary condition to the walls of the plate. The remaining walls use the default slip wall condition.

Here's the geometry and mesh:





And that's the pressure distribution (already multiplied by the fluid density to have values in Pa) on the surface of the plate facing the flow:



The value obtained from the analytical calculation is 3.072 Pa. As you can see, the simulation shows non-uniform pressure distribution with around 1.5-4.2 Pa in the middle and lower (even reaching negative values) around the edges. What can I do to improve the accuracy and get closer to the analytical solution ? The mesh seems to be dense enough for this type of benchmark analysis but maybe I should keep refining it. So far refinement didn't help (the previous mesh was way more coarse and the results were similar). Or is this kind of pressure distribution normal and I can't get a better agreement with the analytical calculations that assume uniform pressure ?