BJERKNES FORCES BETWEEN SMALL CAVITATION BUBBLES IN A STRONG ACOUSTICHELD

The mutual interaction between small oscillating cavitation bubbles (R -0 < 10 mu m) in a strong acoustic field (P-a > 1 bar, f = 20 kHz) is investigated numerically. We assume spherical symmetry and a coupling of the bubble oscillations. Our results show that the strength and eve n the directions of the resulting secondary Bjerknes forces differ con siderably from predictions of the well-known linear theory. This is of immediate consequence for understanding and modeling structure format ion professes in acoustic cavitation and multi-bubble sonoluminescence .