Unsteady pressure and vorticity fields in blade-vortex interactions

The unsteady interaction of a vortex core with a NACA 0015 airfoil is studied in two dimensions. A two-component, three-beam Helium-Neon laser-Doppler Velocimetry system is used to take data in a water tunnel. Ensemble-averaged velocity fields are obtained in the region of the leading edge of the airfoil. Finite-difference algorithms were written to obtain vorticity and pressure in the data field. Computer animation of the unsteady vorticity was accomplished first with a Fortran code written for an Apple Macintosh computer and later with a commercial software package for a SUN Microsystems graphics terminal.