Innovative Flight Instrumentation for Hypersonics

In this proposal we exploit the remote sensing attributes of ultrasound to conduct heat transfer studies on hypersonic propulsion components and vehicle materials. In the Phase I program, we have successfully demonstrated the viability of the ultrasonic method to measure surface temperature, local temperature and heat flux. In a series of laboratory studies, we have remotely measured surface temperature changes of a few degrees Centigrade using sensors located more than 4.5 centimeters from the heated surface. Experiments on laboratory mock-ups replicating typical cooling channel configurations have shown the ability to non-intrusively measure both the temperature of the fluid within the channel and in the region between the channel and the heated surface. One dimensional analytical models and inversion algorithms to accurately extract heat flux from the ultrasonic data have also been developed and demonstrated. Initial investigations on C/C composites show that scattering from multiple interfaces and microstructure complicates the analysis. However, our results suggest that many of the methods applicable to metallic structural components can be applied to C/C composite with appropriate modification on ultrasonic frequency and analysis methods. In the Phase II program we apply these measurement principles to solve thermal transport problems relevant to hypersonic flight.