Inlet Drag and Stability Considerations for Mo = 2.00 Design

Abstract

The results of an experimental study to evaluate the performance and low-flow stability limits of several isolated inlet models are presented. The lowest drag approach to provide large-flow regulation was a bypass device for handling the excess airflow. The use of compression surface modulation or a boundary-layer bleed system to dispose of the excess airflow incurred similar drag penalties which were significantly greater than those for the bypass configuration. A good correlation of low-flow stability range data with a shock-lip geometry parameter is demonstrated. A by-product of this work is the introduction of a drag parameter that allows a more complete approach to quantifying inlet drag characteristics. Nomenclaturebetween lip and normal shock position for slipstream ingestion P = pressure W c = corrected weight flow a, 13 = lip angles 6 = compression surface turning angle 0 = angle between lip and leading edge of the shockgenerating surface 6 = discharge angle Subscripts 0 = freestream 2 = engine face B = bleed exit c = capture e = bypass exit T = total and throat

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