Attenuation and penetration of pulsed supersonic liquid jets—An experimental study

Abstract

Pulsed supersonic liquid (water and diesel fuel) jets in the range of 1500 m/s to 1800 m/s have been produced and examined. A two stage light gas gun was used as a launcher to obtain the pulsed impact (velocity of 700m/s). In this paper, experimental results on the attenuation and the penetration distance of the liquid jets is presented. It was found that the attenuation is relatively high in the first 300 μs of the jet flight. The penetration distance is around 300–500 mm, this depending on the initial velocity, the nozzle geometry and the properties of liquid. The experimental results agree well with the estimation using conventional diesel spray formula. The shadowgraph image shows bow shock wave structures with multiple pulses which tend to enhance atomization and combustion. However, further examination of their atomization related to the jet attenuation and penetration distance is needed.