A supersonic aircraft's intake has been simulated from just upstream of the throat down to the engine face, with a wide bleed slot employed for boundary layer removal and mass flow trimming. A comprehensive experimental survey of the aerodynamic characteristics of the simulated intake has been made for several slot configurations, slot length, rear lip planform and profile all being changed. Rear lip scoop has been employed with one configuration and flow; unsteadiness in the form of pressure fluctuations has also been assessed. The general flow mechanisms prevailing have been identified and in many instances explained either qualitatively or quantitatively using basic gas dynamic relations. For optimum total pressure recovery at the engine face, irrespective of slot configuration, the terminal shock should be located at, or upstream of, the front lip. If limited amounts of scoop are applied when using a bluff rear lip improvements in bleed total pressure recovery may be obtained with no deterioration in the optimum engine face pressure recovery. The bluff lip also suppresses shear layer unsteadiness, as does a reduced void depth or reduced slot width.
|Date of Award||1980|