Flow visualization and hot gas ingestion characteristics of a vectored thrust STOVL concept

摘要

Hot gas ingestion, the entrainment of heated engine exhaust into the inlet flow field, is the key development issue for advanced short takeoff and vertical landing aircraft. A 9.2 percent scale short takeoff and vertical landing (STOVL) hot gas ingestion model was designed and built by McDonnell Douglas Corporation (MCAIR) and tested in the NASA Lewis Research Center 9 by 15 foot Low Speed Wind Tunnel (LSWT). The test was conducted over a range of headwind velocities from 10 to 23 kn and nozzle exhaust temperatures from 500 to 1000 F. The model was also tested over a range of model heights above the ground plane (0.20 to 12 in.) and a range of nozzle pressure ratios from 1.3 to 4.00. A copper vapor laser was used to create an illuminated flow field for flow visualization with the model in and out of ground effects. Results are presented showing the flow field visualization which occurs when the model was in and out of ground effects. The effect of hot gas ingestion on the compressor face temperature rise and several other parameters are also presented. The environmental effects of the hot gas on the ground and its effect on the acoustic loads as a function of the model height above the ground are also presented.