Estimated aerodynamics of all-body hypersonic aircraft configurations

The results of analyses for estimating the aerodynamics of a representative family of all-body hypersonic aircraft configurations are presented.The configuration body shape is a delta planform with an elliptical cone forebody and an elliptical cross-section afterbody.Semiempirical and theoretical predictions of the aerodynamic characteristics of the forebody are compared with available experimental data to show the reliability of the basic methods.Results are presented for aerodynamic performance, surface temperatures, and static longitudinal and directional stability.Aerodynamic perf&rmance of the all-body configurations is presented in the form of th'e'effe'ct'pn co.mplete configuration maximum lift-to-drag ratio of Mach number, configuration geometry, and maximum allowable leading-edge temperature.Variations in the basic all-body shape were investigated using three independent;',-shape: parameters; body leading-edge sweep, position of breakpoint between forebody and afterbody', and ratio of maximum cross section to body planform area.The third shape parameter had the strongest influence on the aerodynamic performance.Studies of the radiation equilibrium surface temperature show that the temperatures on the lower surface resulting from the inherent low lift loading of the all-body configuration are less than would be expected for higher lift-loading configurations.A brief analysis of vehicle stability and control showed that using a canard for trim instead of horizontal fins reduced trim drag penalties.17.Key Words (Suggested by Author(s)) Aerodynamics All-Body Hypersonic Aircraft 19.Security Classif.(of this report) Unclassified 18. Distribution Statement Unclassified-Unlimited 20.Security Classif.(of this page) 21.No. of Pages 22. Price" Unclassified 37 $3.00For sale by the National Technical Information Service, Springfield, Virginia 22151 SYMBOLS a speed of sound, ft/sec a o speed of sound at sea level, ft/sec n u major/minor axis ratio of fore body elliptical cross sections span 2 AR aspect ratio, plan area bpiN fin span, ft Cj coefficient multiplying sin a in CL expression C 2 coefficient multiplying sin 2 a in CL expression C£) RR bluntness drag coefficient for body (nose) Crjop bluntness drag coefficient for fins (leading edges) CDFR friction drag coefficient for body C-DpF friction drag coefficient for fins CD-induced drag coefficient Cn zero-lift drag coefficient C-DOR zero-lift drag coefficient for body C-DOF zero-lift drag coefficient for fins CD D pressure drag coefficient for body CD p pressure drag coefficient for fins CDY drag coefficient of type X CD Y drag coefficient of ty pe X for fins lift coefficient c, c p P? D C PBASE e h KM moment coefficient about body center of gravity pressure coefficient two-dimensional truncated base pressure coefficient pressure coefficient on configuration afterbody base of natural logarithms altitude, ft Mach number coefficient for Crj.equation body length, ft forebody length, ft MAX _L