The Temperature Dependent Behaviour of a Cavitation Bubble Field

Experimental investigations on cavitation bubble fields are reported. By application of the two frequency excitation method, some information can be obtained concerning the size and density distribution of the bubbles. Due to the nonlinearity of the bubbly medium combination frequency products develop. Thus the low frequency cavitation noise spectrum is reflected into the high frequency range around the image signal. This way the subharmonic emissions of the bubble field are observed. In comparison to experimental investigations of the temperature dependent behaviour of the bubble field numerical evaluations based on a modified Keller-Miksis-model have been performed. After calculation of the cavitation threshold pressures, the amplitudes of the subharmonic components of the bubble oscillation dependent on temperature and equilibrium bubble size are compared to the experimental results assuming a normal distribution of the bubble sizes.