No abstract

Measurements and calculations of the phase speed of disturbances observed in a small shock tube are made, via cross-correlation of successive frames from focusing schlieren videography and double focused laser differential interferometry. The efficacy of the latter technique for measuring slender-body hypersonic boundary-layer instability wave-packets is also demonstrated. Shock tube experiments are performed to provide a known velocity input to both sensors for comparison, and measurements of phase velocity are made behind the reflected shock. Power spectral density curves from the FLDI and focusing schlieren from shock tube experiments at similar conditions are compared with each other and with pitot tube results, and reasonable agreement is found to the frequency limits of the sensors.