NASA NTRS1965
Force tests were conducted at a Mach number of 6.0 on nose-cylinder-flare bodies to determine the effect of nose shape, cylinder length, flare angle, and flare length on the longitudinal aerodynamic characteristics. A particular investigation was conducted to determine the effect of flare angle for constant flare length, surface area, and diameter. Results indicated that at a Reynolds number of approximately 0.92 x l0 (exp 6) (based on body diameter), the boundary-layer separation effects were significant only with respect to the slope of the normal-force and pitching-moment curve at low angles of attack. The variations of the aerodynamic characteristics with the various parameters were, in general, similar to those predicted by Newtonian theory below a flare angle of 30 degrees and a ratio of flare base diameter to cylinder diameter of less than approximately 2.2. The limiting diameter ratio is consistent with the extent of the low-constant dynamic-pressure region near the body caused by the bow-shock influences as predicted by axisymmetric characteristic theory. The effects of the various parameters for the flares that exceeded the limiting diameter ratio follow the trends predicted by the computed flow-field properties. The axial force for these flare configurations at zero angle of attack was, in general, computed within 10 percent by using these properties. For a constant flare length and surface area the flare effectiveness increased with increasing flare angle; however, for constant flare diameter only the axial-force coefficient was affected by flare angle.