Publication de 6 numéros par an
ISSN Imprimer: 2152-5102
ISSN En ligne: 2152-5110
Indexed in
Laser Doppler Anemometry Study of Oscillating Bubbles
RÉSUMÉ
The use of laser Doppler anemometry (LDA) to investigate the non-stationary signal from an oscillating bubble produced by an underwater spark is presented. The major benefit of using LDA to measure the flow over traditional techniques such as hydrophones is that the method is non-intrusive and therefore does not influence the flow. The non-stationary Doppler signal is analyzed in a novel way using wavelets to produce the instantaneous velocity of the flow at the measurement point and hence pressure. This can be used to obtain the bubble oscillation period, maximum radius and energy. The form of the energy transfer from the circuit to the bubble in terms of the spark gap width is found to be non-linear and an empirical relationship for the decay of the bubble peak pressure with distance from the bubble center is obtained.