In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 114, No. 4_Supplement ( 2003-10-01), p. 2322-2322
Abstract:
The motion of vibrating bodies in a surrounding fluid is often used to infer the transport properties of the fluid. A new sensor configuration is presented that consists of a rotating imbalance source radiating into an unbounded fluid medium. Under these circumstances, the reaction of the fluid medium onto the vibration source includes a steady state torque that opposes the applied torque required to sustain the rotating imbalance. This reaction torque causes a shift in frequency of the vibration source. The frequency shift is related to the density of the surrounding fluid medium and vibration source characteristics. A description of measurements taken with a rotating-imbalance source located in unbounded water and air is provided. The total mass, eccentricity, and length of the source were 4.1 kg, 3.28(10−4) kg & lt;th & gt;m, and 0.432 m, respectively. Motive torque to drive the imbalance was provided by a permanent-magnet dc motor. For an applied dc voltage that caused the source to operate at a nominal frequency near 150 Hz, a frequency shift of approximately 11 Hz was observed when the source was moved from air to water. Experimentally measured frequency shifts compared favorably with predictions provided by a nonlinear steady state model of the source and surrounding medium.
Type of Medium:
Online Resource
ISSN:
0001-4966
,
1520-8524
Language:
English
Publisher:
Acoustical Society of America (ASA)
Publication Date:
2003
detail.hit.zdb_id:
1461063-2
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