ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

2pSA12. Flow-induced self-noise on a spherical sensor.

Andrew R. Jones

Gerald C. Lauchle

Graduate Program in Acoust. and Appl. Res. Lab., Penn State Univ., P.O. Box 30, State College, PA 16804

An experimental effort to characterize the low Reynolds number flow-induced self-noise on a spherically shaped inertial sensor operating underwater is described. The transducer is a small geophone encased in a sphere, 76.2 mm in diameter. The sphere itself is cast from a 4:1 by volume of polystyrene microballons and epoxy resin, which yields a slightly negatively buoyant bluff body that is capable of sensing weak fluctuations in velocity such as those resulting from acoustic disturbances. When such a sensor is used in ocean environments, a spurious self-noise signal oftentimes exists due to low velocity currents. The research described in this paper quantifies this flow-induced noise signal as a function of the sphere diameter Reynolds number (0 All posters will be on display from 12:45 to 4:45 p.m. To allow contributors an opportunity to see other posters, contributors of odd-numbered papers will be at their posters from 12:45 to 2:45 p.m. and contributors of even-numbered papers will be at their posters from 2:45 to 4:45 p.m.