Effects Of Reynolds Number And Model Support On The Supersonic Aerodynamic Chacteristics Of A 140 Included Angle Cone

Effects of Reynolds Number and Model Support on the Supersonic Aerodynamic Chacteristics of a 140° Included-angle Cone

An investigation has been made in the Langley Unitary Plan wind tunnel to determine the effects of Reynolds number and sting-support interference on the static aerodynamic characteristics of a 140 deg-included-angle cone. Base pressures and forces and moments of the model were measured at Mach numbers of 1.50, 2.00, 2.94, and 4.00 for ratios of sting diameter to model diameter that varied from 0.125 to 0.500 through an angle-of-attack range from about minus 4 deg to 13 deg. The Reynolds number, based on model diameter 4.80 in. was varied from 161,000 to 415,000.

NASA Technical Memorandum

Sting Interference Effects as Determined by Measurements of Dynamic Stability Derivatives, Surface Pressure, and Base Pressure for Mach Numbers 2 Through 8

Wind tunnel tests were conducted to provide support interference information for planning and directing wind tunnel tests at supersonic and hypersonic Mach numbers. Sting-length and sting-diameter effects on base and surface pressures of a blunt 6-deg cone with a sliced base were investigated at Mach numbers 2, 3, 5, and 8. Dynamic stability tests on a blunt 7-deg cone were also conducted at Mach numbers 2, 5, and 8. The objectives of the 7-deg cone tests were to define critical sting lengths as determined by the measurement of dynamic stability derivatives, static pitching moment, and base pressure. Two frequencies of oscillation were investigated, and data were obtained for laminar, transitional, and turbulent boundary-layer conditions at the model base. The data from the 6- and 7-deg cone tests showed that the critical sting length depended on the interference indicator, Mach number, angle of attack, state of the model boundary layer, and frequency of oscillation. The critical sting length was generally less for models with turbulent boundary layers than for those with laminar boundary layers. A critical sting length of 2.5 model diameters was determined to be suitable for all test conditions that produced a turbulent boundary layer at or ahead of the model base.