UNSTEADY VORTEX DYNAMICS AND SURFACE PRESSURE TOPOLOGIES ON A FINITE PITCHING WING

A straight wing having an NACA 0015 cross section and rectangular plan form was attached to a circular splitter plate. This configuration was pitched at a constant rate to angles exceeding the static stall angle . The unsteady, vortex-dominated flow that developed over the wing and splitter plate was characterized in detail using surface pressure mea surements and flow visualization. Both types of data showed that the l eading-edge vortex underwent profound three-dimensional alterations to cross section and convection over the entire wing span. These changes in leading-edge vortex structure and kinematics were correlated with prominent spanwise variations in force coefficients. When appropriatel y dissected, visualization results and pressure data suggested physica l mechanisms to account for these three-dimensional variations in unst eady forces and surface pressures.