[devanson]

Hi All,
I am facing a different issue here. I want to simulate flow over MAV (Micro Air Vehicle). I created two Mesh in ANSYS workbench. Both are Tet mesh, with one Boundary layer (at Y+ = 1, calculated according to my Re).

My flow condition are, air as flow medium, Re from 20,000 to 200,000 and different angle of attack from -5 to 20 degree.

With first mesh (without boundary layer mesh), simulate flow in fluent using Spallart Allamarus model. My Cl (Coefficient of Lift) is in good match with experiment data). My Cd (Coeff of Drag) is deviating from Exp. My Drag from simulation is too low from experimental values.

Now, tried with second mesh with boundary layer. And simulated the same flow. Now the problem is that, My drag coefficient is even 3% lower than before one (without boundary layer mesh).

This is what confusing me. With good boundary layer mesh, my fluent solver should be able to resolve my sub-viscous boundary layer which helps in better predicting drag co-efficient. But I am getting reverse.

Is there anythng wrong? Am I missing anything. If any details required, I am very happy to provided. I want to resolve this issue. Please help me out..

[devanson]

Fond answer... Please close this thread...