BASE PRESSURE AT SUPERSONIC SPEEDS ON TWO-DIMENSIONAL AIRFOILS AND ON BODIES OF REVOLUTION WITH AND WITHOUT FINS HAVING TURBULENT BOUNDARY LAYERS

摘要

An analysis has been made of available experimental data to show the effects of most of the variables that are more predominant in determining base pressure at supersonic speeds. The analysis covers base pressures for two-dimensional airfoils and for bodies of revolution with and with¬out stabilizing fins and is restricted to turbulent boundary layers. The present status of available experimental information is summarized as are the existing methods, for predicting base pressure.nA simple semiempirical method is presented for estimating base pres¬sure. For two-dimensional bases, this method stems from an analogy established between the base-pressure phenomena and the peak pressure rise associated with the separation of the boundary layer. An analysis made for axially symmetric flow indicates that the base pressure for bodies of revolution is subject to the same analogy. Based upon the methods presented, estimations are made of such effects as Mach number, angle of attack, boattailing, fineness ratio, and fins. These estima¬tions give fair predictions of experimental results.