THE DOWNSTREAM INFLUENCE OF MASS TRANSFER AT THE NOSE OF A SLENDER CONE
POLYTECHNIC INST OF BROOKLYN NY
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The influence of localized mass transfer at the nose of a slender cone under hypersonic flow conditions was studied by experimental and theoretical means. Two gaseous coolants, nitrogen and helium are injected through a porous plug subtending a half angle of 30 degrees. The effect of the mass transfer on the shock shape, pressure distribution, heat transfer and transition are investigated. The theoretical analysis involved a study of the effect of mass transfer on the shock stand-off distance and leads to an inviscid flow parameter permitting the experimentally determined shock shape and pressure distribution to be extrapolated to other than test conditions and to other coolant gases. Significant reductions in heat transfer are obtained with injection. Indeed with small amounts of helium injection the peak heating is found to occur downstream on the cone and to be an order of magnitude less than would occur at the stagnation point without mass transfer. With nitrogen early transition is found to occur so that local heating rates are actually increased over those prevailing at the same Reynolds number without injection.
- Fluid Mechanics