Novel Measurement Techniques for Liquid Rocket Spray Characterization

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 presense of multiple particles within the measurement probe valume, 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, siz, 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.