Reason for Lift Coefficient Error
 

Hi everyone,

I've been running some simulations for an airfoil at various angles of attack (up to 6 degrees) with properties;

Re = 1000, laminar model, second order density based solver, free stream velocity = 1 (varied viscosity to obtain Re).

I'm getting lift and drag coefficient errors of order 5-10%, which for what I'm doing is ample. However, my drag coefficient is much more accurate than my lift. I'm curious as to what mechanisms would cause this, as I would expect drag to have a greater error (due to difficulties in resolving boundary layer).

Is there anything in particular in a mesh or Fluent setup which would affect lift in this way?

On a side note, I've also noticed that my 3D tests (allowing wing tip effects) are much more accurate than my 2D. I didn't expect this either. My 3D models are simple swept face versions of my 2D ones.

Thoughts?

Regards,
Josh