Hydrodynamic simulations of bubble collapse and picosecond sonoluminescence
- Lawrence Livermore Natl. Lab., L-200, P. O. Box 808, Livermore, CA 94550 (United States)
- Lawrence Livermore Natl. Lab., Livermore, CA 94550 (United States)
Numerical hydrodynamic simulations of the growth and collapse of a 10-[mu]m air bubble in water were performed. Both the air and the water are treated as compressible fluids. The calculations show that the collapse is nearly isentropic until the final 10 ns, after which a strong spherically converging shock wave evolves and creates enormous temperatures and pressures in the inner 0.02 [mu]m of the bubble. The reflection of the shock from the center of the bubble produces a diverging shock wave that quenches the high temperatures ([gt]30 eV) and pressures in less than 10 ps (FWHM). The picosecond pulse widths are due primarily to spherical convergence/divergence and nonlinear stiffening of the air equation of state that occurs at high pressures. The peak temperature at the center of the bubble is affected strongly by the ionization model used for the air. The results are consistent with recent measurements of sonoluminescence that had optical pulse widths less than 50 ps and 30-mW peak radiated power in the visible. [This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.]
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 7007080
- Journal Information:
- Journal of the Acoustical Society of America; (United States), Vol. 96:5; ISSN 0001-4966
- Country of Publication:
- United States
- Language:
- English
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