Near- and farfield measurements of aero-optical effects due to propagation through hypersonic flows

* The research reported herein was performed by the Arnold Engineering Development Center (AEDC), Air Force Materiel Command. Work and analysis for this research were performed by Sverdrup Technology, Inc., AEDC Group, technical services contractor for AEDC; SY Technology, Inc., Huntsville, Alabama; and WaveFront Sciences, Albuquerque, New Mexico. Further reproduction is authorized to satisfy needs of the U. S. Government. # Associate Fellow, AIAA + Senior Member, AIAA ABSTRACT A series of aero-optics tests have been carried out at Mach 7 in the Hypervelocity Wind Tunnel 9 (Tunnel 9) at the Arnold Engineering Development Center (AEDC). The test-bed used for the measurements were two flat plates which had sapphire windows mounted in titanium frames. Aero-optic measurements included near-field phase and intensity measurements made with two wavefront sensors, farfield point spread functions made with an imaging camera, and high frequency optical tilts (bore sight error) made with an X-Y Detector. Ancillary measurements of pressure and heat transfer on the testbed plates were also made. The aero-optic measurements coupled with a variety of computations resulted in phase and intensity maps, bore sight errors, contained energy diameters (CED’s) and point spread functions (PSF’s). Comparisons between the various measurements are made to ascertain aerodynamic effects, instrument errors, facility-induced errors and measurement uncertainties.