Problem of force variation
 

Hi CFX-5 users I am new user of CFX-5. I am simulating flow around an axisymmetric cylindrical body and want to calcualte forces acting on it. When i vary discretization scheme from linear to second order forces change drastically. Also mesh refinement affects force magnitude a lot. Can any body give general instructions how to get accurate results. For example mesh refinement , discretization schemes, turbulence model. Particularly I am much interested in knowing how much turbulence model affects the magnitude of forces. Thanks