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