Oscillating airfoil

ganesh

Dear friends,

I am trying to solve the inviscid flow past an oscillating airfoil. My unsteady solver uses dual time stepping procedure and I have modified Roe scheme by incorporating the grid velocities, seeing to it that the Geometric conservation law is satisfied. Though I do get a hysterisis oval for my Cl-angle of attack curve , my cl values are nearly one half of the computed values. The test case is AGARD CT5. Can anyone who have worked in this area give some suggestions about any possible problem that I overlooked. Also could you give the way to calculate cl. I calculate cl by integrating the pressures over the airfoil.

Thanks in advance,

Ganesh