STEADY FLOW EJECTOR RESEARCH PROGRAM
LOCKHEED AIRCRAFT CORP MARIETTA GA
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An investigation was conducted to determine the jet thrust augmentation factor under steady flow conditions for rectangular parallel-divergent wall ejector configurations with multiple primary nozzles. CONCLUSIONS The use of an inlet having lemniscate contours for the secondary flow entrance increases ejector performance. An ejector of optimum design using 4 rows of primary nozzles and a constant inlet radius will give about 60 of the theoretical maximum thrust augmentation. Use of curved-wall diffuser entrances rather than mitered diffuser entrances increases ejector thrust augmentation. An optimum design ejector using 4 rows of primary nozzles, a lemniscate secondary inlet, and curved-wall diffuser entrance will have a thrust augmentation of about 61.5 of the theoretical maximum. The optimum position of the primary nozzles is dependent on the nozzle arrangement used and on the shape of the secondary inlet. Ejectors having nonsymmetrical diffusers had lower values of thrust augmentation than symmetrical ejectors. The use of other than a constant area mixing section decrease ejector performance. The best arrangement of multiple primary nozzles is one which apportions an equal geometrical share of secondary flow area to each nozzle. The rows of primary nozzles must be centered in the ejector span to avoid sharply reduced performance.