Comparison of Experiment and Analysis for a High Primary Mach Number Ejector
Abstract
Analytical predictions derived from ARL TR-75-0205 are compared with test results for two ejectors while have the same inlet geometry; however, one has a constant area mixing section and no subsonic diffuser, while the other has a tapered mixing section, a constant area supersonic diffuser and a subsonic diffuser. The purpose of the first configuration is to provide well defined experimental conditions for the comparison of analysis and experiment, while the second configuration is designed to give optimum performance. The design goal in this case is a total ejector pressure ratio of five at a mass flow ratio (primary to secondary) of five. For both ejector configurations the experiments agreed very satisfactorily with the analysis. However, some ambiguity is involved in the predictions for the optimized ejector. This is due to the difficulties in predicting the pressure distribution during mixing. The present experiments make it apparent that the optimum performance is inherently connected with a near constant pressure distribution. More testing is necessary to confirm this result. Should it hold, ejector optimization could be made more reliable. For the present comparison the analysis of ARL TR 75-0205 is extended to include off-design conditions for the primary supersonic ejector nozzles.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1977
- Accession Number
- ADA042555
Entities
People
- Earnest F. Fretter
- Siegfried H. Hasinger
Organizations
- Flight Dynamics Laboratory