TITLE:
Momentum Transfer on Underwater Shock Generation Induced by Pulsed Laser Irradiation with Thin Metal
AUTHORS:
Rokhsan Ara Hemel, Hiroyuki Hirahara, Kento Takahashi
KEYWORDS:
Momentum transfer, Underwater shock wave, Longitudinal wave
JOURNAL NAME:
Open Journal of Fluid Dynamics,
Vol.6 No.3,
September
13,
2016
ABSTRACT: The present paper has investigated the momentum transport phenomena of underwater
shock wave generation in terms of photo-acoustic wave with a very thin metal.
The shock wave was induced by a pulsed-laser irradiation. In order to clarify the
momentum transport mechanics in this phenomenon, we have been considered the
momentum and energy transport from laser to metal, and metal to water. A numerical
solution of thermo-elastic wave in metal has been obtained to estimate a fundamental
gain of the longitudinal wave. Then, the underwater shock wave phenomena
have been analyzed by adapting compressible fluid dynamics with suitable boundary
condition between the solid and liquid. We had performed an experiment as well and
observed the shock wave with optical system. The aim of the research is to estimate
the underwater shock wave strength theoretically. The metal region was calculated by
Laplace transformation of heat conduction and wave equations. The water region
was simulated by MacCormack’s method. Some of boundary conditions have been
examined and the acceleration condition has been adopted at the interface. The simulated
results show a good agreement with experimental result, consequently the
momentum transfer mechanism from longitudinal wave to underwater shock wave
has been cleared in the present report.