The Navier-Stokes analysis code developed earlier has been extended to examine the flow about a two dimensional airfoil at high incidence placed in an oscillating freestream. The governing Navier-Stokes equations are solved by the SIMPLER algorithm in the orthogonal streamline coordinate system generated by conformal mapping. The QUICK scheme of Hayase and the three-point backward differencing are incorporated for convective and time derivatives to accurately resolve the flow field.
Flow about a NACA 0012 airfoil section at two different angles of attack, i.e., 20˚ and 30˚, is examined for steady and sinusoidally oscillating freestream conditions. The results including the flow patterns and characteristics, such as $C_L$, $C_D$ and separation, are presented for various reduced frequency and amplitude combinations.
