A spark-generated bubble model with semi-empirical mass transport

Abstract

This paper describes the time evolution of bubbles generated by underwater electrical discharges. The oscillations of these high-temperature vapor and plasma bubbles generate acoustic signatures similar to the signatures generated by air guns, underwater explosions, and combustible sources. A set of model equations is developed that allows the time evolution of the bubble generated by a spark discharge to be calculated numerically from a given power input. The acoustic signatures produced by the model were compared to previously recorded experimental data, and the model was found to agree over wide ranges of energy and ambient pressure on several characteristic values of the acoustic signatures. The bubble period in particular matched very well between model and experiment, indicating that the total energy losses predicted by the model over the oscillation of the bubble were approximately correct, although no reliable information was gained about the relative magnitudes of the individual energy loss mechanisms examined. The bubble period and the minimum rarefaction pressure were found to depend on depth, while the peak pressures in the expansion and collapse pulses and the acoustic energy in the expansion pulse were not found to depend on depth over the parameter ranges investigated.

Experimental Study of Pulsed Discharge Underwater Shock‐Related Properties in Pressurized Liquid Water

“…Schaefer's results showed that the larger the P H , the smaller the bubble maximum radius and the higher the peak frequency [23]. Jeffrey conducted a theoretical study revealing that the bubble period and the minimum rarefaction pressure were dependent on P H , while the first peak pressures of WSW were unrelated to P H when P H < 0.9 MPa [24]. Based on Jeffrey's results, Lu presented a new model including bound-bound transitions in the calculation of the thermal radiation power [25].…”

Numerical and Experimental Study of the Interaction of a Spark-Generated Bubble and a Vertical Wall

“…Spark generators have been used for studying bubbles in a liquid for quite a long time [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. DYNAFLOW, INC. has several test chambers that can be used to simulate full-scale bubble dynamics, and is equipped with flow diagnostics tools including high speed photography and pressure measurement capabilities.…”

Application of pulsed power generated high power ultrasound to waste comminution and the recovery of metals

“…The channel transforms into a cavity filled with a gas which continues to expand even after the internal pressure becomes lower than the external hydrostatic pressure, P<P 0 , due to inertia of the surrounding water flow. A rarefaction pressure pulse is radiated in this stage of the bubble development [1].…”