Tutorial on acoustic fluid loading of structures

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Any vibrating structure is loaded by the fluid surrounding it. Whether air, water, or something else, the fluid loading adds a spatially distributed resistance (in phase with the velocity of vibration) and reactance (out of phase with the velocity of vibration) over the structural surfaces. The resistance absorbs energy, and damps structural vibrations. The reactance is either mass-like, effectively adding to the structural density and reducing resonance frequencies and vibration amplitudes; or stiffness-like, increasing resonance frequencies. Usually, mass-like reactance is caused by fluids external to a structure, and stiffness-like reactance is caused by enclosed volumes of fluids. This tutorial uses analytic methods to compare and contrast external and internal fluid loading on a flat rectangular plate and demonstrates the effects of fluid loading on plate vibration. The well-known stiffening effect of the internal Helmholtz resonance is demonstrated for a thin panel and a shallow entrained cavity. Strong coupling between interior cavity and structural modes is also demonstrated. The differences between heavy (water) and light (air) external fluid loading are shown, with significant reductions in resonance frequencies and peak vibration amplitudes for water loading.

Original languageEnglish (US)
Title of host publicationProceedings of INTER-NOISE 2021 - 2021 International Congress and Exposition of Noise Control Engineering
EditorsTyler Dare, Stuart Bolton, Patricia Davies, Yutong Xue, Gordon Ebbitt
PublisherThe Institute of Noise Control Engineering of the USA, Inc.
ISBN (Electronic)9781732598652
DOIs
StatePublished - 2021
Event50th International Congress and Exposition of Noise Control Engineering, INTER-NOISE 2021 - Washington, United States
Duration: Aug 1 2021Aug 5 2021

Publication series

NameProceedings of INTER-NOISE 2021 - 2021 International Congress and Exposition of Noise Control Engineering

Conference

Conference50th International Congress and Exposition of Noise Control Engineering, INTER-NOISE 2021
Country/TerritoryUnited States
CityWashington
Period8/1/218/5/21

All Science Journal Classification (ASJC) codes

  • Acoustics and Ultrasonics

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