Effects of Liquid Second Viscosity in High-Amplitude Sonoluminescence

The well-known Rayleigh-Plesset (RP) equation is the base of nearly all hydrodynamical descriptions of sonoluminescence (SL) phenomenon. A major deficiency of this equation is that it accounts for viscosity of an incompressible liquid and compressibility, separately. By removing this approximation, we have modified the RP equation considering effects of liquid second viscosity. This modification exhibits its importance at the end of an intense collapse, so that the new model predicts appearance of a new picosecond bouncing during high amplitude sonoluminescence radiation. This new bouncing produces very sharp (sub-picosecond) peaks on the top of sonoluminescence pulse. These new behaviors are more remarkable for higher driving pressures and lower ambient temperatures.