An Evaluation of Jet Simulation Parameters for Nozzle Afterbody Testing at Transonic Mach Numbers
Final rept. Jan 1975-Jun 1976
ARO INC ARNOLD AFS TN
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The objective of this investigation was to evaluate various jet simulation parameters in an attempt to establish a method of matching hot jet interference with cold jet flows. Successful parameters were determined based on their ability to correlate integrated afterbody pressure drag, a measurement of aerodynamic interference, for jet flows of varying total temperature. Data used in this investigation were obtained from experiments conducted in the AEDC Propulsion Wind Tunnel 16T with three different isolated nozzleafterbody configurations at free-stream Mach numbers from 0.6 to 1.5. Gas temperature effects on pressure drag were acquired with a convergent nozzle utilizing an airethylene burner to produce gas temperatures from 540 to 3,300 R. In addition, the jet effects of varying internal nozzle geometry, specifically nozzle divergence half-angle and nozzle exit-to-throat area ratio, were investigated utilizing high-pressure air as the nozzle exhaust gas. Jet simulation parameters were evaluated for jet flows where nozzle exit-to-throat area ratio was varied from 1.0 to approximately 1.5 and where divergence half- angle was varied from 0 to 10 deg.
- Jet and Gas Turbine Engines