Experimental Evaluation of Inlet Drag Characteristics in the Transonic Mach Number Regime.

摘要

The report presents the results of a test program and analyses to determine the drag of supersonic inlets operating at transonic Mach number conditions. The total inlet drag of a set of 18 axisymmetric inlets, 3 F-4 inlet model configurations, and 7 configurations of a uniquely designed Opposed-Ramp inlet were measured. Special test equipment was utilized to measure the absolute value of additive and cowl drags (total inlet drag). The test equipment, instrumentation, test summary, model description and the wind tunnel test results are presented and discussed in detail. Theoretical methods were used to compute the inlet drag and surface pressure distribution for comparison with the axisymmetric inlet data. The basis of these calculations are presented and modifications to the theory are shown which provide a method of estimating inlet drag at high subsonic Mach number conditions. Comparison of the inlet drag determined from the integration of pressure measurements and that obtained with the drag measurement apparatus are compared showing the superiority of the latter data. The axisymmetric inlet test models were designed so that the test data would show the effects of the most significant design parameters. (Author)