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Speaker: Professor Robert A. Frederick, Jr., and Mr. Brian Sweeney
Affiliation: Director, UAH Propulsion Research Center, and The University of Alabama in Huntsville, respectively


An overview of recent research at the UAH Propulsion Research Center and prospects for future research directions will be presented by Professor Robert Frederick, the Center Director. After this overview, Mr. Sweeney, a PhD Candidate at UAH, will provide a technical talk on recent experiments pertaining to like-doublet injectors. A cold-flow experiment was conducted to analyze the effect of varying the impingement distance of like-doublet injectors. An initial experiment was carried out to determine the jet breakup length as a function of injection velocity. The results agreed well with existing empirical breakup length correlations. The like-doublet test program comprised a combination of three impingement angles, three injection velocities, and three different lb/li ratios. It was found that the lb/li ratio has a profound effect upon the resulting spray and atomization quality. For lb/li ratios greater than one, the impingement process produces a flat sheet that disintegrates into waves of ligaments and droplets. Larger impingement angles and jet velocities correspond with smaller droplet sizes and greater spray uniformity. An unsteady sheet forms when the lb/li ratio is equal to one. For lb/li less than one, no sheet is formed. Instead, most of the droplets formed from the disintegration of the jet pass through the impingement point. Occasional droplet collisions occur at the impingement point producing a shower of small droplets down the centerline of the spray. Also, the atomization frequency was found to be proportional to the injection velocity but independent of both the impingement angle and lb/li ratio.



Prof. Frederick is Director of the UAH Propulsion Research Center. He has directed over $8 million in research and published extensively. Topics include combustion stability of liquid injectors, solid propellant combustion, hybrid fuel combustion, thermal stability of hydrocarbon fuels, and characterization of rocket plume emissions. Dr. Frederick is an Associate Fellow of the AIAA and former chairman of the AIAA Hybrid Rocket Technical Committee. He has been a technical advisor to NATO in solid propulsion. Dr. Frederick received his Ph.D. in Aeronautics and Astronautics from Purdue University in 1988. His professional experience includes positions at Allison Turbine Engines, the Air Force Rocket Propulsion Laboratory, and Sverdrup Technology, AEDC Group. He joined UAH in 1991. Mr. Sweeney is a PhD student at UAH in Mechanical and Aerospace Engineering and is an Alabama Space Grant Fellow.

Date(s) - Aug 11, 2015
3:00 pm - 4:00 pm


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