[Lorenzo C.]

I'm trying to perform a transient simulation of flow around an airfoil.
The simulation is at Re=50000 with an incompressible fluid.
As expected i found oscillatory drag and lift coefficients due to the beginning of von karman vortexes phoenomena.
I'm performing different simulation maintaining the Re=50000, but changing parameters like material's viscosity and density, and velocity inlet, to analyze the sensitivity of these drag and lift coefficients.
I supposed that at same Reynolds and same shape of the airfoil, these coefficients are almost constant (reading some paper i found tabulated values for differently shaped airfoils).
Actually happens that increasing the velocity by a factor 10 ^2 these coefficients are scaled by the same factor.
How can I explain this behaviour?
Thank you very much for the help, I can't find a logical explanation.