Applied Acoustics and Ultrasonics
The first focus of this laboratory is the propagation of sound in natural bodies of water. The facilities include a wet lab testing facility with computer-controlled instrumentation for acoustic propagation experiments.
The lab also contains two workstations for computational modeling. In addition to lab and computational efforts, at-sea research projects are planned through collaborations with other regional facilities.
The current research thrust is the study of sound propagation in the shallow water surf zone. Ongoing projects include the characterization of acoustic propagation through bubble clouds. An in situ device has been developed to measure the acoustic impedance of bubbly assemblages and (eventually) the sea bottom and a novel acoustic array has been developed and successfully towed behind an autonomous underwater vehicle in tests run in conjunction with Woods Hole Oceanographic Institution.
In additon, BU investigators are working in close collabortation with the Naval Surface Warfare Center (Panama City, FL) to develop a novel technique for buried mine detection using time reversal acoustics. Activities include scaled experiments in the BU lab as well as lake experiments at NSWC-PC.
The second major facet of the lab is devoted to cutting-edge techniques for ultrasound imaging and for cavitation remediation studies related to the Oak Ridge National Laboratory Spallation Neutron Source (SNS) facility. The Medical Imaging Testbed (MedBED) is one of four research and development laboratory facilities created as part of the NSF Engineering Research Center for Subsurface Sensing and Imaging Systems (CenSSIS).
Facilities include a large-water-filled, ultrasound scan tank (with precision positioners, supporting computers and acoustic-electronic instrumentation) for general purpose ultrasound research and two diagnostic ultrasound scanners for biomedical imaging research. The SNS work features a acoustic resonator designed for detecting free gas bubbles in flowing mercury and a laser cavitation system for generating reproducible bubble cloud collapse near boundaries under well controlled aqueous conditions. Cloud collapse diagnostics include high speed photography, acoustic emission measurements, and boundary surface vibrations measured using a laser Doppler vibrometer.