hi *,

is it possible to calculate drag force on a cylinder (2D) in a creeping flow? I use FV formulation with only diffusive fluxes. So R_e := ZERO, and corresponding drag calculated from the Lamb formula is also zero. And whatever I take for inflow velocity I never get streamline separation after cylinder so is it at all possible to validate such a solver with zero peclet number (no advection)?

thank you

If you've set Re=0, there are no viscous forces (an inviscid flow) so there will be no drag force. If there is no drag force, the streamlines will not show any separation. You will need a positive value for Re to generate any forces. However, I am saying this from a purely fluid mechanics POV.