On the application of holographic interferometry to axisymmetric air flows

While the resolve of interferometric measurements of general, three dimensional asymmetric flow fields requires the use of multiple views of the fields, most wind tunnel applications are limited to a single view along a single line of sight through the field. For this restriction, the reduction of interferometric measurements is limited to axisymmetric flows. Accordingly, this research is directed toward resolving basic problems associated with the reduction of interferometric data of real, axisymmetric flows. The problem of coping with insufficient optical data is resolved by the development of an interferometric measuring technique that has a pseudo-continuous measuring resolution of 15 microns, the problem of suppressing the amplification of noise and scatter in the optical data is resolved by developing a general numerical data reduction process, a method for isolating flow fields that are interior to central fields is developed, a unique computational interferometer process applicable to the study of asymmetric flows is developed, and direct experimental application is made to supersonic boundary layer flow on sharp tip cons.