Brajnikoff, George B.
This report contains the results of an experimental investigation made at Mach numbers between 1.36 and 2.01 of the total-pressure recovery attainable with a model having a ramp ahead of an annular inlet for the purpose of reducing the entrance Mach number by means of an oblique shock wave. It was found that the recovery improved considerably with increasing ramp angle and that a model with a 15 degree ramp produced approximately four-fifths of the recovery through a normal shock wave occurring at the free-stream Mach number. Use of ramp angles greater than 15 degrees resulted in unsteady flow through the induction system and a reduction in recovery.
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