EXPERIMENTAL INVESTIGATION OF THE EFFECT OF ENTRANCE WIDTH-TO-HEIGHT RATIO ON THE PERFORMANCE OF AN AUXILIARY SCOOP-TYPE INLET AT MACH NUMBERS FROM 0 TO 1.3

摘要

As a part of an investigation of variable-area auxiliary inlets intended to provide for the variation of engine air requirements with speed and altitude, three auxiliary scoop inlets were tested in combination with a nose inlet at Mach numbers from 0 to 1.3 at zero angle of attack. These auxiliary inlets had inlet areas equal to 12 percent of the main-inlet area. Two values of scoop width-to-height ratio were investigated for inlets with sharp lips, and a third model was tested with rounded lips. Comparison with the results of a preliminary investigation indicates that gains of about 7 percent in the effective-thrust ratio were attained at a Mach number of 1.1 by reducing the scoop widthto-height ratio from 13.4 to 2.4.