FLIGHT MEASUREMENTS AT MAGH NUMBERS FROM 1.1 TO 1.9 OF THE ZERO-LIFT DRAG OF A TWIN-ENGINE SUPERSONIC RAM-JET CONFIGURATION

摘要

A flight investigation was conducted to determine the zero-lift drag characteristics of a twin-engine supersonic ram-jet configuration, which were needed to make performance calculations below the design Mach number. Data were obtained over a Mach number range from 1.1 to 1.9 for two power-off ram-jet models - with and without nacelles - to supplement the performance data obtained from previous tests at higher supersonic speeds. The Reynolds number, based on fuselage length, ranged from 53 X 106 at a Mach number of 1.1 to 118 x 106 at a Mach number of 1.9. The external drag of the nacelle units, which included the drag of the inboard wedge-type struts, outboard fairings, and nacelles and their mutual interference drag, was determined and accounted for approximately 60 percent of the total external drag of this configuration.