Low Drag, Underwater Acoustic Source for Sea Surface-based Mine Sweeping Navy STTR FY2005 Sol No.: Navy STTR FY2005 Topic No.: N05-T029 Topic Title: Low Drag, Underwater Acoustic Source for Sea Surface-based Mine Sweeping Proposal No.: N054-029-0296 Firm: Applied Physical Sciences Corp. 2 State Street Suite 300 New London, Connecticut 06320-6356 Contact: William Milewski Phone: (860) 440-3253 Web Site: www.aphysci.com Abstract: A critical design feature for a towed mine countermeasure platform is low drag. In this STTR we propose to integrate an efficient acoustic source within a low drag body to perform influence mine sweeps behind an unmanned surface vehicle. To develop the optimum system a trade-study is proposed during Phase I to examine electronically-powered transducers and novel hydroacoustic concepts. The transducer design will be capable of radiating high levels of energy into the surrounding fluid within the design envelope. For the hydroacoustic option, different mechanisms of cavitation will be examined for the hydroacoustic source to accurately mimic a ship signature. Numerical techniques will be used to develop the hydrodynamic shape of the towed body that will minimize the overall drag. A key component of the system is that it will be designed to easily integrate into the Navy's current mine countermeasure platforms, providing immediate benefits. Benefits: If successful, the proposed research will significantly improve the US Navy's capabilities in acoustic influence mine sweeping. A low drag acoustic source will make it feasible for the Navy to conduct mine countermeasure operations using unmanned surface vehicles which are low cost assets, offer the potential to stay on station for longer periods, and reduce the risk to human life. As a result, our commercialization efforts will focus primarily on the US Navy. We anticipate developing a complete system consisting of an automated handling system, acoustic source with required subsystems, and low drag tow body. If we proceed with the transducer as the acoustic source, we will assess potential port security applications that require a low drag tow body with an acoustic transmitter. One possible application is a mobile version of the Underwater Loudhailer (see description in Section 4.2). Return