Pressure distributions and shock-standoff distances were obtained in air for three blunt, stream-alined cylinders at a nominal Mach number of 15. Equilibrium stagnation temperature was about 3,600o rj which corresponds to an isentropic exponent in the stagnation region of the model of about 1.25 for the present test conditions. All models were highly cooled. Reynolds numbers based on free-stream properties for equilibrium flow and on cylinder diameter were 2400 and 6200. The experimental data indicated nonequilibrium flow in the stagnation region for some of the models. Viscosity effects appeared to be negligible. Several theories for computing cylinder pressure were examined. Comparisons with experiment showed that some of the existing methods provided good estimates of the pressures on the blunt cylinders. Further evaluation of the theories showed that the blast-wave analogy accurately described the influence of isentropic exponent, as well as Mach number and nose drag, on the cylinder pressure. Perfect-gas characteristics solutions for a wide range of Mach number, nose drag, and isentropic exponent were correlated by the blast-wave parameter and were well represented by a simple, but useful, equation in blast-wave form.
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