The attenuation of blast waves using liquid sheets

The blast wave propagated into the atmosphere from the sudden ignition of a rocket motor in a launch tube has been simulated using a shock tube. Conventional approaches to reducing the intensity of this pressure wave use tube extensions, perforated tubes and combinations of boxes and baffles at the tube exit. This paper presents results of an investigation of the effect of liquid sheets as inertial energy absorbers to reduce the blast intensity. Experiments with two-dimensional and axisymmetric tubes with water sheets adjacent to the tube exit are described and are supported by a theoretical model. Attention is directed towards the absolute reduction in blast intensity and also to the changes induced in the frequency spectrum of the propagated disturbance.