Calculation of Pressures on Bodies at Low Angles of Attack in Supersonic Flow

An empirical relation is developed for calculating the pressures over blunted noses. This relation is matched with a new and improved second-order shock-expansion method to calculate approximate surface pressure distributions over blunted and pointed axisymmetric bodies at incidence. Modifications and extensions to the basic second-order shock-expansion method include 1) a new method for locating the position where the secondorder .shock-expansion method is matched with the blunt-nose pressure relation, 2) an "exact" method for calculating the pressure gradient around a corner, 3) a new expression for calculating pressures around pointed cones at incidence, and 4) a new method for calculating angle-of-attack solutions. The method was found to predict the overexpansion near the juncture of sphere-cones at Mach numbers as low as 1.5. Results were found to compare well with experimental data and exact flowfield computations on blunted cones with and without flares at all Mach numbers greater than 1.5 and angles of attack up to 15 deg. The simplicity and efficiency of the computer program make it attractive for preliminary design applications.