Revised Scaling of Optical Distortions Caused by Compressible, Subsonic Turbulent Boundary Layers

Abstract

New measurements of optical aberrations caused by a compressible subsonic turbulent boundary layer are presented. These new measurements are based on more-accurate Malley Probe measurements made possible by developing new wind- tunnel test sections that greatly reduced vibration corruption that imprints itself on the Malley Probe's small-aperture, probe-beam deflection-angles. These new measurements give more-accurate levels of optical distortions for laser propagation through boundary layers, lowering previously-obtained values by ~ 30%. Using a similarity analysis based on these new measurements, a rigorous approach of extracting boundary-layer-related optical information from partially corrupted spectra is proposed and demonstrated by applying it to previously-obtained, vibration-corrupted measurements. Optical spanwise and streamwise length scales for a boundary layer are also presented and these statistical data is used to develop a method of creating realizations of 2-D wavefronts.