A solution procedure for two- and three-dimensional unsteady viscous flows

An efficient computational procedure for solving three-dimensional unsteady turbulent flows is described. The consistently split Linearized Block Implicit (LBI) scheme is used in conjunction with the QR operator scheme to solve an approximate form of the Navier-Stokes equations in generalized nonorthogonal coordinates employing physical velocity components. As a demonstration calculation the turbulent oscillating flow over a flat plate corresponding to the experiment of Karlsson is considered in both two and three dimensions. New inflow boundary conditions are proposed which yield physically plausible solutions near the upstream boundary. The results obtained agree both qualitatively and quantitatively with Karlsson's data and shed new light on the controversy concerning the interpretation of the skin friction phase angle as a function of reduced frequency.