Pulsation behavior of a bubble generated by a deep underwater explosion

Abstract

This paper reports on experiments involving deep underwater explosion (UNDEX) that were conducted in a pressure container. The bubble pulsation behavior due to the deep UNDEX is recorded by a high-speed camera for equivalent depths up to 350 m. The bubble images show that although the shape of the explosive package affects the bubble shape at the initial moment, the bubble easily becomes spherical in shallow water which is 0.8m and 100m depth, but never becomes spherical during the whole first pulsation in deep water which is 200m, 300m and 350m in this paper. Solutions of the Rayleigh–Plesset equation fit well with the experimental data, and the value of the polytropic index γ of the gaseous detonation products changes from 1.25 to 1.3 as the depth is increased. Finally, empirical laws governing the pulsation of a deep-UNDEX bubble are established. The experimental pulsation period and that from the Rayleigh–Plesset equation agree with that obtained empirically, but the maximum radius is smaller than the empirical one. This phenomenon shows that the water depth not only creates a high hydrostatic pressure for the bubble but also changes the energy-release process of a deep UNDEX.

Investigation of the Effect of Nozzle on Underwater Detonation Shock Wave and Bubble Pulsation

“…The common evolution of the underwater explosive charge is obtained, including the processes of expansion, shrinking, deformation, and water jet formation. Moreover, the phenomenon of almost uniform pressure distribution and non-uniform velocity distribution within the bubble is found, which is basically in accordance with the results of experimental studies on underwater explosive charge performed by Liang [15] and Poplavski [16]. The experimental research on the gas jet generated by underwater detonation employs mostly pressure measurements and high-speed photography combined with particle image velocimetry (PIV) techniques to obtain the pressure oscillation characteristics of the field and the typical phenomena of the bubble evolution, such as bubble expansion, shrinking, and necking [17][18][19].…”

Comparison of Maximum Peak Pressures of Free Underwater Explosion by Numerical Modeling and Empirical Expressions

“…Where R 0 is the radius of the sphere of the explosive charge. Zamyshlyayev i Yakovlev [9,10] propose the following expressions for the maximum pressure depending on the dimensionless distance 0 R R :…”

A shockwave calculation method for aluminized explosive of deep water explosion based on the Kirkwood‐Bethe model

“…The deep-sea explosion experiment are both expensive and technically difficult, it is economical and feasible to use pressure vessels to study the shockwave [7][8][9][10][11][12][13][14][15]. However, due to the strength requirements of the pressure vessels itself and the presence of reflected waves on the wall, the experiment conditions are strictly limited.…”