Technologies for Rapid Affordable Hypersonic Flight Testing

Innovative measurement methods and instruments are needed to advance the state-of-art of hypersonic flight. Improved thermal transport measurement methods speed development, improve understanding, and enhance our ability to validate analytical models and hardware for numerous propulsion and aeroshell applications. Recent studies have shown that in many hypersonic applications ultrasonic-based temperature and heat flux measurements offer distinct advantages over conventional methods. The transient temperature response is limited only by the velocity of sound and not the thermal mass of the sensor. Measurements can be made remotely, which prevents the disturbance of the measured quantity and removes the sensor from the harsh thermal environment. Measurements can be made without modifying the structure in any way e.g. drilling. In spite of these advantages, ultrasonic thermometry has not found widespread use. One reason for this limited use is the lack of low-cost, compact, dedicated, instrumentation which takes full advantage of the ultrasonic-based methods. In this proposal, we fill this gap by developing and demonstrating a multi-channel ultrasonic-based temperature and heat flux measurement capability. This innovation will be initially applied to boundary layer transition measurements in ground-based experiments, but will have the potential for application in a host of in-flight hypersonic experiments. BENEFIT: Ultrasonic thermometry offers unique capabilities to hypersonic vehicle development. Improved thermal transport measurement methods speed development, improve understanding, and enhance our ability to validate analytical models and hardware for numerous propulsion and aeroshell applications. The non-intrusive nature of the method is particularly attractive for hostile environment encountered in hypersonic flight. The immediate market for this technology is primarily in military applications where there is a need for improved thermal transfer measurement tools to drive the development and evaluation of hypersonic materials and components. In addition to the applications in hypersonic vehicle and propulsion systems, the ultrasonic temperature sensor technology has applications in the areas of space lift, space platform, combustion research, and missiles. There is also a potential commercial market in areas where thermal transport data is needed in relatively inaccessible regions such as combustion chambers, reactors and in some glass molding operations.