Variable-Area Subsonic Diffuser Study
Final rept. 1 Jul 1975-30 Jun 1976
ARO INC ARNOLD AFS TN
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An experimental development program was conducted to investigate the performance of a variable-area subsonic diffuser. The project goal was to improve the static pressure rise ratio of exhaust gas diffusers used with subsonic, high-bypass-ratio, front fan engines during direct-connect testing in ground test facilities. A one-tenth scale model of the TF-39 turbofan engine was used in the experiment. Diffuser performance data were recorded during model engine operation with cold air at five simulated power settings with five diffuser configurations. Test cell and engine cowl surface pressures were recorded to determine the influence of the exhaust gas diffuser on these pressures. Data from all configurations were analyzed to determine the effect of the exhaust gas diffusers on test cell and engine cowl pressures and to determine the diffuser pressure rise ratio. Test cell and engine surface pressure data were not affected by the diffuser configuration. The static pressure rise ratio of one variable-area diffuser configuration tested exceeded that of all others and a conventional 5-deg half-angle subsonic diffuser.
- Jet and Gas Turbine Engines