The structure of compressible starting vortices

The structures of highly two-dimensional shock-induced compressible starting vortices were investigated. Density distributions across the vortex were measured by dual-pulsed holographic interferometry. Pressure profiles of the vortex were measured by fast-response miniature Kulite transducers. From these two independent measurements the velocity profile was calculated using the radial momentum equation. The detailed vortex structure is similar to that from the tip of a wing and consists of four well-defined regions: a core region, a logarithmic region, a transition region, and an inviscid region. The distribution of circulation of the vortices can be expressed by a set of empirical formulae. The proportionality constants of the logarithmic region were found to be 0.43±0.01 for three different two-dimensional vortices.Presently at U.S. Army Aeroflightdynamics Directorate, ATCOM, NASA-Ames Research Center, Moffett Field, CA 94035Professor