Impingement Flow-Fields for Tube-Launched Rockets

摘要

An experimental program has been conducted to measure the pressures acting on the face of a launcher assembly due to the impingement of an underexpanded rocket exhaust flow. For the range of variables considered in the present test program, the following conclusions are made. (1) The most important characteristic dimension for the impingement fow-field is the ratio of the plume diameter to the diameter of the open tube. (2) When the stagnation pressure is relatively low most of the exhaust gas is swallowed by the open tube. High surface pressures are limited to the region near the rim of the open tube. (3) Once a critical value of Pt1 is exceeded, the central shock wave increases in size and in strength. (4) The opening of one tube adjacent to the launch tube has only a slight effect on the pressure distribution present on the face of the launcher. (5) The maximum pressure differentials that act across the missile itself occur when the flow is supercritical and the nozzle-exit plane is near the face of launcher.