APPROXIMATE SIMILARITY PRINCIPLE FOR A FULL-SCALE STOVL EJECTOR

Full-scale ejector experiments are expensive and difficult to implemen t at engine exhaust temperatures. For this reason the utility of using similarity principles, in particular the Munk and Prim principle for isentropic now, was explored. Static performance test data for a full- scale thrust augmenting ejector were analyzed for primary flow tempera tures up to 1560-degrees-R. At different primary temperatures, exit pr essure contours were compared for similarity. A nondimensional flow pa rameter is then used to eliminate primary nozzle temperature dependenc e and verify similarity between the hot and cold flow experiments. Und er the assumption that an appropriate similarity principle can be esta blished, properly chosen performance parameters were found to be simil ar for both hot flow and cold flow model tests.