Preliminary results of water tunnel acoustic measurements using a time reversal mirror

A concept demonstration test was recently conducted at the Garfield Thomas Water Tunnel at the Penn State University Applied Research Laboratory using a time reversal mirror to acquire acoustic measurements of a cavitation noise source. The objective of the test was to demonstrate improved acoustic measurement capabilities compared to conventional underwater acoustic measurement techniques. A preliminary analysis of the data indicates an increased signal-to-noise ratio resulting from the time-reverse playback of recorded data compared to real-time measurements made using either omnidirectional or sum-beam sensors. Experimental results are presented, including a novel method for source localization based on the difference between the time-forward and time-reverse playback of recorded data. [Work supported by ONR Code 334, Naval Surface Warfare Center Carderock Division, and the Applied Research Laboratory.]