Flight test of a rugged scramjet-inlet temperature and velocity sensor

Abstract

The performance of a gas temperature and velocity sensor based on tuneable diode laser absorption spectroscopy (TDLAS) of oxygen in a scramjet engine inlet during a flight test is discussed. This is the first flight-tested TDLAS sensor designed specifically for measuring gas velocity of a scramjet inlet flow under flight conditions. The robustness and stability of the sensor design in dynamic load conditions were made evident by the quality of the data delivered after a very unstable and high-g launch scenario. The scramjet did not reach the targeted test altitude-velocity regime. However, analysis of the low-altitude data determined pressure and temperature in the inlet and showed that an adequate signal-to-noise ratio was obtained for high-speed velocity measurements at altitudes up to at least 30 km.