PRELIMINARY INVESTIGATION OF A SUBMERGED AIR SCOOP UTILIZING BOUNDARY-LAYER SUCTION TO OBTAIN INCREASED PRESSURE RECOVERY

摘要

A submerged air scoop consisting essentially of a conventional scoop located in a dimple in the fuselage surface has been investigated preliminarily at low speeds. The inlet had an entrance width-height ratio of about 3.7 and a steep approach ramp (19° at the entrance) which provided a short and compact installation. The internal and external flow characteristics of the basic inlet without boundary-layer control were studied by means of pressure and tuft surveys over a wide range of Inlet-Telicity ratio. Studies were then conducted to determine the effects of boundary—layer control, suction-slot location and model configuration, and variations of boundary-layer thickness on inlet performance. A self-activating boundary-layer bypass was incorporated in the final arrangement tested. An indication of the external drag was obtained by wake surveys downstream of the scoop and by pressure surveys in the boundary-layer suction flow.