Journal of Fluid Mechanics

Papers

Experimental study of the behaviour of mini-charge underwater explosion bubbles near different boundaries

C. F. HUNGa1 and J. J. HWANGFUa2 c1

a1 Department of Engineering Science and Ocean Engineering, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan

a2 Chung Shan Institute of Science and Technology Chemical System Division, P.O. Box 90008-17 Longtan, Taoyuan County, 325, Taiwan

Abstract

This work experimentally studies the behaviour of underwater explosion bubbles near different boundaries. The results are compared with theoretical and experimental data on cavitation bubbles. Although explosion and cavitation bubbles behave similarly on a macroscopic level, there are still some differences, most of which are from the explosive nature of the explosion bubble. The relationship between bubble migration and the Kelvin impulse, surface inertia m* and surface stiffness k* is investigated. We found that none of them comprehensively predicts the migration of both cavitation and explosion bubbles when boundary elasticity is considered. This elasticity should be considered as a relative value with respect to bubble size. On the other hand, the phase between local vibration of boundaries and the pulsation of bubbles could be a useful predictive index of bubble migration. When using research results developed for cavitation bubbles in relation to explosion bubbles, the material presented here may be useful for pointing out their similarities and differences.

(Received January 16 2009)

(Revised November 28 2009)

(Accepted December 04 2009)

(Online publication April 07 2010)

Correspondence:

c1 Email address for correspondence: sandy.hwangfu@msa.hinet.net

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