Non-Intrusive Measurement Techniques for Scramjet Ground Test Environments

The objective of this proposal is to develop a new visualization sensor based on high resolution diode laser absorption spectroscopy, for the non-intrusive measurement of flow-field species in hydrogen-fueled scramjet engine ground tests. The proposed instrument would measure the extinction of incident light levels from a tunable diode laser source chosen to emit at wavelengths which correspond to a particular rotation-vibration level for a particular molecule. Temperature and concentration measurements will be provided by incorporation of multiple wavelengths and time multiplexing. During the Phase I program we will develop and construct a prototype sensor and the sensor models to help optimize the design of the sensor as a combustion diagnostic tool for development of hypersonic scramjet systems. A limited demonstration program, using the LENS facilities at CUBRC, will be performed to evaluate the sensor functionality and to examine facility integration concepts. This diagnostic will provide valuable information on the fuel/air stream mixing and combustion processes in general, during hypersonic flow. This information will further support CFD modeling of the fuel injection.