SOME REYNOLDS NUMBER EFFECTS ON THE PERFORMANCE OF EJECTORS WITHOUT INDUCED FLOW
ARO INC ARNOLD AFS TN
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The variation of minimum cell pressure ratio with nozzle total pressure level is presented for various ejector configurations having axially symmetric nozzles located on the centerline of cylindrical ducts. Seven nozzles were tested, using unheated air, in combination with two cylindrical ducts of different diameter and of length to diameter ratio equal to or greater than five. The significant parameter involving nozzle total pressure level was found to be the unit Reynolds number at the nozzle exit times the nozzle throat diameter. An empirical method, which is usually accurate to within 20 percent of the experimental values, was developed for predicting the variation of minimum cell pressure ratio with nozzle total pressure level for ejectors using 18-deg conical nozzles. Curves are presented which permit the estimation of minimum cell pressure ratio for ejectors using isentropic or other contoured nozzles similar to those used in this investigation. A similarity parameter is presented which denotes the necessary condition for the equal performance of two geometrically similar ejector systems using different driving fluids.
- Fluid Mechanics