Free-flight Investigation of Heat Transfer to an Unswept Cylinder Subjected to an Incident Shock and Flow Interference from an Upstream Body at Mach Numbers Up to 5.50


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Heat-transfer rates have been measured in free flight along the stagnation line of an unswept cylinder mounted transversely on an axial cylinder so that the shock wave from the hemispherical nose of the axial cylinder intersected the bow shock of the unswept transverse cylinder. Data were obtained at Mach numbers from 2.53 to 5.50 and at Reynolds numbers based on the transverse cylinder diameter from 1.00 x 106 to 1.87 x 106. Shadowgraph pictures made in a wind tunnel showed that the flow field was influenced by boundary-layer separation on the axial cylinder and by end effects on the transverse cylinder as well as by the intersecting shocks. Under these conditions, the measured heat-transfer rates had inconsistent variations both in magnitude and distribution which precluded separating the effects of these disturbances. The general magnitude of the measured heating rates at Mach numbers up to 3 was from 0.1 to 0.5 of the theoretical laminar heating rates along the stagnation line for an infinite unswept cylinder in undisturbed flow. At Mach numbers above 4 the measured heating rates were from 1.5 to 2 times the theoretical rates.
















FFA Meddelande


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Avhandling


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Convective Heat Transfer in Planetary Gases


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Equilibrium convective heat transfer in several real gases was investigated. The gases considered were air, nitrogen, hydrogen, carbon dioxide, and argon. Solutions to the similar form of the boundary-layer equations were obtained for flight velocities to 30,000 ft/sec for a range of parameters sufficient to define the effects of pressure level, pressure gradient, boundary-layer-edge velocity, and wall temperature. Results are presented for stagnation-point heating and for the heating-rate distribution. For the range of parameters investigated the wall heat transfer depended on the transport properties near the wall and precise evaluation of properties in the high-energy portions of the boundary layer was not needed. A correlation of the solutions to the boundary-layer equations was obtained which depended only on the low temperature properties of the gases. This result can be used to evaluate the heat transfer in gases other than those considered. The largest stagnation-point heat transfer at a constant flight velocity was obtained for argon followed successively by carbon dioxide, air, nitrogen, and hydrogen. The blunt-body heating-rate distribution was found to depend mainly on the inviscid flow field. For each gas, correlation equations of boundary-layer thermodynamic and transport properties as a function of enthalpy are given for a wide range of pressures to a maximum enthalpy of 18,000 Btu/lb.