Accession Number : AD0888634

Title :   Experimental Test Results and Comparisons with Simple Theory for the FDL-6C Configuration at Subsonic Mach Numbers.

Descriptive Note : Technical rept. Feb 68-Aug 70,

Corporate Author : AIR FORCE FLIGHT DYNAMICS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s) : Gord, Peter R.

Report Date : AUG 1971

Pagination or Media Count : 104

Abstract : The current class of hypersonic reentry vehicles must have the capability to perform conventional landings, preferably without recourse to variable geometry. Because of this requirement, considerable emphasis in recent years has been directed towards the low speed characteristics of slender reentry configurations. Subsonic test data on this class of vehicles is limited and scattered, and an adequate subsonic theory is not available. This report presents subsonic test data for a typical vehicle, obtained at a nominal Mach number of 0.19 and over an angle-of-attack range of -4F to a maximum of 32F. Efforts to improve the subsonic performance through a parametric variation of the lower surface bottail angle and aspect ratio were evaluated, and significant increases in lift-to-drag ratio were observed. A discussion of a modified form of the slender body theory applicable at high angles of attack and including the effect of viscous cross flow is presented. Comparisons are made with test data on several of the shapes tested, and an appendix is included which compares the theory with data from other sources. In general the theory can adequately predict the slope of the normal force curve and provide a first order approximation of the pitching moments. (Author)

Descriptors :   (*LIFTING REENTRY VEHICLES, LANDING), SUBSONIC CHARACTERISTICS, WIND TUNNEL MODELS, AERODYNAMIC CONFIGURATIONS, ANGLE OF ATTACK, ASPECT RATIO, EXPERIMENTAL DATA.

Subject Categories : Aerodynamics
      Unmanned Spacecraft
      Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE