Ground Effect Characteristics of a Two-Dimensional Hypersonic Configuration

Abstract

The National Aerospace Plane (NASP) cone guration was designed to suit the propulsion needs at hypersonic speeds.Itslowerfuselagesurfaceformed thepropulsion system with an obliqueshock compression ramp, scramjet combustion module, and a single expansion ramp nozzle. To minimize drag, the nose was very thin and the upper surfacewas nearly e at. How each of these surfaces contribute to itspoor low-speed and ground effect performance is demonstrated. This poor performance is characterized by signie cant power-on lift reduction that is intensie ed by ejector action while in ground effect. The NASP aerodynamic characteristics were e rst measured on a threedimensionalmodelasfunctionsofangleofattack,groundproximity, andthrustcoefe cient. Then to separatethreedimensional effects from the key problems with this cone guration, the tests were repeated with a two-dimensional model based on the fuselage centerline geometry.