EXPERIMENTS WITH OSCILLATIONS OF NONSPHERICAL GAS-BUBBLES OSCILLATINGIN A LIQUID-SHOCK-TUBE

Non-linear oscillations of non-spherical gas bubbles in a liquid are s tudied experimentally. Bubbles are excited into oscillation using a li quid-shock-tube. Bubble shapes are monitored by a rotating mirror came ra. Pressure waves radiated by oscillating non-spherical bubbles are p icked up by a needle hydrophone. The paper concentrates on the analysi s of pressure records and associated acoustic energies. Experimental d ata are compared with theoretical predictions for spherical bubbles. I t is found that even highly non-spherical bubbles radiate intensive pr essure waves of almost the same form and strength as predicted by the theory for spherical bubbles. Abrupt changes in the length of the thir d oscillation period occur when increasing the driving pressure step s trength. Similarly, anomalies in the measured peak and trough pressure s are found. This report is an extension of a previous paper, which wa s devoted to non-linear oscillations of spherical gas bubbles.