Unsteady Navier–Stokes solutions for a NACA 0012 airfoil Original Research Article

Unsteady compressible Navier–Stokes equations are solved using third-order Roeʹs scheme for the inviscid fluxes and second-order central difference scheme for the viscous fluxes. The governing equations are solved using finite-volume implicit scheme in body-fitted curvilinear coordinate O-grid system with first-order time accuracy. Computations are reported for NACA 0012 airfoil at two angles of attach 30∘ and 53∘, M=0.20, Rc=3000. Results are compared with those reported in literature and the unsteady behaviour of lift and drag coefficients has been predicted with respect to amplitude and bimodal variation. Also detailed unsteady behaviour at discrete time steps for one cycle has been investigated and presented in this paper.