Interest of microwave techniques to study a bubble field induced by ultrasonic Cavitation

The emergence of bubbles in a liquid under the action of ultrasonic power wave is called ultrasonic cavitation. The effects induced by this phenomenon cover a large application field. Studies for its understanding are often performed with a single bubble. We here study a global bubble field, whose use is inescapable for the ultrasonic cavitation applications. We show that a hyperfrequency cavity technique permits to measure the void rate of a cavitation bubble field, and also to evaluate the bubble size distribution. Experimental results in water confirm the validity of this method. Further developments will emphasize on the evolution of the void rate at the acoustic period scale and on the investigation of spatial bubble distribution in the cavitation field.