摘要

A vertical ballistic range is constructed to investigate sonic boom properties. The flow field around a launched projectile in the range is visualized by both one- and two-dimensional color schlieren methods. The flight Mach number of the projectile is lower than 1.5. The flow visualization shows that some disturbances, such as blast waves, vortex rings, and jets, are generated when the projectile is launched. The blast waves have strong influences on the flow field around the projectile because the propagation velocity of the blast waves is close to the velocity of the projectile. Setting a few baffle plates at the exit of the barrel effectively reduces the strength of the disturbances. The present color schlieren method extended to two-dimensional analysis is an effective one to visualize a complicated supersonic flow field like the present experiment.