SBIR-STTR Award

Development of advanced diagnostic techniques and spray characterization methodologies are essential to the understanding of the complex spray process and for validating state-of-the-art CFD codes that are available for describing the spray process. Novel diagnostic techniques and measurement schemes have been proposed for evaluation in this proposal. The application of the well-established phase Doppler interferometry to the characterization of dense rocket injector sprays requires the ability of PDPA signal processors to reliable detect the simultaneous presence of multiple particles within the measurement probe value, and accurately estimate the size and velocity of each of the multiple particles. The feasibility of using a frequency domain processor, namely, the Doppler Signal Analyzer (DSA) will be evaluated in this program. Also, the integration of the PDPA with another newly evolving diagnostic, namely, rainbow refractometry/ thermometry, for the reliable measurement of droplet temperatures, size, and velocity in complex reactive sprays will be investigated in this program. The development of improved rainbow signal processing methodologies is important for such an application. During the Phase I program, the feasibility of extending rainbow refractometry for studying liquid-liquid mixing and droplet collision/coalescence will also be undertaken. Finally, a novel fluorescent tagging technique will be evaluated for the purpose of studying gas-gas mixing in gaseous rocket injectors.

Development of advanced diagnostic techniques and spray characterization methodologies are essential to the understanding of the complex spray process and for validating state-of-the-art CFD codes that are available for describing the spray process. The application of the phase Doppler interferometry to the characterization of dense rocket injector sprays requires several new developments. This includes validation algorithms for rejecting erroneous measurements, signal processors that can handle high speed, high velocity, and short transit times, the ability to detect the presence of multiple particles within the probe volume and accurately estimate the size and velocity of each of the multiple particles. Prototype hardware and software for extending the phase Doppler interferometry into dense sprays will be developed under this Phase II program. An advanced rainbow signal processors and techniques for validating the rainbow signals will be developed under the Phase II program. Sophisticated software for data analysis and interpretation will also be developed under the Phase II program. The prototype of the integrated diagnostics will be tested using controlled experiments and in realistic rocket engine spray environments. The prototype hardware and software developed under this Phase II program will be delivered to the Phillips Lab, Edwards Air Force Base.