Stability Characteristics of a Conical Aerospace Plane Concept

Wind tunnel investigations were conducted as part of an effort to develop a stability and control database for an aerospace plane concept across a broad range of Mach numbers. The generic conical design used in these studies represents one of a number of concepts being studied for this class of vehicle. The baseline configuration incorporated a 5° cone forebody, a 75.96° delta wing, a 16°leading-edge sweep deployable canard and a centerline vertical tail. Tests were conducted in the following NASA-Langley facilities spanning a Mach range of 0.1 to 6:30- by 60-Foot Tunnel,14- by 22-Foot Subsonic Tunnel, Low Turbulence Pressure Tunnel, National Transonic Facility, Unitary Plan Wind Tunnel, and the 20 Inch Mach 6 Tunnel. Data were collected for a number of model geometry variations and test conditions in each facility. This paper highlights some of the key results of these investigations pertinent to stability considerations about all three axes. The effects of the canard on pitch stability, the vertical tail on lateral-directional stability, and forebody geometry on yaw asymmetries are also discussed. In addition, low-speed power effects, Reynolds number effects, and damping characteristics are presented. Fundamental causes for the aerodynamic characteristics observed are discussed and the implications on aircraft trim and controllability are also addressed. Comparisons of experimental stability data with results from the engineering predictive code APAS (Aerodynamic Preliminary Analysis System) are also provided.