A preliminary data report on ground pressure disturbances produced by the Fairey Delta 2 in level supersonic flight

Abstract

Measurements have been made of pressure disturbances on the ground resulting from approximately straight and level supersonic flight of the Fairey Delta 2 in the altitude range 30,000 ft to 3,500 ft above sea level, and with flight Mach numbers up to about 1.5. Pressure against time, flight histories, radar plots, and other data are given. The results, with allowance for refraction, show satisfactory agreement with the estimates of peak bang pressures and impulses given by Warren. At low flight Mach numbers, the bang intensities were below theory, and the spread of the bangs each side of the flight track was limited; these effects were attributed to atmospheric refraction. On a few flights, the normal 'N' pressure/time pattern was followed closely by additional pressure disturbances which, on one occasion, reached a peak positive value of nearly 2 lb/ft². These effects seem attributable to flight of an alternately accelerated and decelerated nature.