Challenges of investigating fluid-elastic lock-in of a shallow cavity and a cantilevered beam at low mach numbers

Kristin Lai Fook Cody, Stephen A. Hambric, Martin L. Pollack

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

2 Citations (Scopus)

Abstract

At low flow Mach numbers, fluid-elastic lock-in may occur when a shear layer instability interacts with an adjoining or nearby structure and the resulting vibration of the structure reinforces the shear layer instability. Despite the significant amount of study of lock-in with acoustic resonators, fluid-elastic lock-in of a shear layer fluctuation over a cavity and a structural resonator is not well understood and has not been thoroughly studied. Design of an experimental system is described and preliminary diagnostics are addressed as a basis for a platform for developing a fundamental understanding of the feedback mechanism, analytical models for predicting and describing fluid-elastic lock-in conditions, and the roles of the fluid and structural dynamics in the process. Features of the system investigated here include design for characterization of modal excitation of a beam-like structure from the shear layer fluctuation, isolation of the predominant instability source to the shear layer fluctuation over the cavity, variation of the cavity size to identify critical parameters that govern fluidelastic lock-in, and alteration of the inflow boundary layer momentum thickness. So far, lock-in between the cavity and the distributed elastic resonator has not been achieved. Further investigations to determine the role of the source and resonator attributes are underway.

Original languageEnglish (US)
Title of host publicationAmerican Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA
Pages253-261
Number of pages9
DOIs
StatePublished - Dec 1 2005
Event2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005 - Orlando, FL, United States
Duration: Nov 5 2005Nov 11 2005

Publication series

NameAmerican Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA
Volume32 NCA

Other

Other2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005
CountryUnited States
CityOrlando, FL
Period11/5/0511/11/05

Fingerprint

Mach number
shear layers
Resonators
cavities
Fluids
fluids
resonators
Acoustic resonators
Structural dynamics
Fluid dynamics
Analytical models
Momentum
Boundary layers
Feedback
dynamic structural analysis
fluid dynamics
boundary layers
isolation
platforms
momentum

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Acoustics and Ultrasonics

Cite this

Cody, K. L. F., Hambric, S. A., & Pollack, M. L. (2005). Challenges of investigating fluid-elastic lock-in of a shallow cavity and a cantilevered beam at low mach numbers. In American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA (pp. 253-261). (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA; Vol. 32 NCA). https://doi.org/10.1115/IMECE2005-79162
Cody, Kristin Lai Fook ; Hambric, Stephen A. ; Pollack, Martin L. / Challenges of investigating fluid-elastic lock-in of a shallow cavity and a cantilevered beam at low mach numbers. American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. 2005. pp. 253-261 (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA).
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abstract = "At low flow Mach numbers, fluid-elastic lock-in may occur when a shear layer instability interacts with an adjoining or nearby structure and the resulting vibration of the structure reinforces the shear layer instability. Despite the significant amount of study of lock-in with acoustic resonators, fluid-elastic lock-in of a shear layer fluctuation over a cavity and a structural resonator is not well understood and has not been thoroughly studied. Design of an experimental system is described and preliminary diagnostics are addressed as a basis for a platform for developing a fundamental understanding of the feedback mechanism, analytical models for predicting and describing fluid-elastic lock-in conditions, and the roles of the fluid and structural dynamics in the process. Features of the system investigated here include design for characterization of modal excitation of a beam-like structure from the shear layer fluctuation, isolation of the predominant instability source to the shear layer fluctuation over the cavity, variation of the cavity size to identify critical parameters that govern fluidelastic lock-in, and alteration of the inflow boundary layer momentum thickness. So far, lock-in between the cavity and the distributed elastic resonator has not been achieved. Further investigations to determine the role of the source and resonator attributes are underway.",
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Cody, KLF, Hambric, SA & Pollack, ML 2005, Challenges of investigating fluid-elastic lock-in of a shallow cavity and a cantilevered beam at low mach numbers. in American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA, vol. 32 NCA, pp. 253-261, 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005, Orlando, FL, United States, 11/5/05. https://doi.org/10.1115/IMECE2005-79162

Challenges of investigating fluid-elastic lock-in of a shallow cavity and a cantilevered beam at low mach numbers. / Cody, Kristin Lai Fook; Hambric, Stephen A.; Pollack, Martin L.

American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. 2005. p. 253-261 (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA; Vol. 32 NCA).

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

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N2 - At low flow Mach numbers, fluid-elastic lock-in may occur when a shear layer instability interacts with an adjoining or nearby structure and the resulting vibration of the structure reinforces the shear layer instability. Despite the significant amount of study of lock-in with acoustic resonators, fluid-elastic lock-in of a shear layer fluctuation over a cavity and a structural resonator is not well understood and has not been thoroughly studied. Design of an experimental system is described and preliminary diagnostics are addressed as a basis for a platform for developing a fundamental understanding of the feedback mechanism, analytical models for predicting and describing fluid-elastic lock-in conditions, and the roles of the fluid and structural dynamics in the process. Features of the system investigated here include design for characterization of modal excitation of a beam-like structure from the shear layer fluctuation, isolation of the predominant instability source to the shear layer fluctuation over the cavity, variation of the cavity size to identify critical parameters that govern fluidelastic lock-in, and alteration of the inflow boundary layer momentum thickness. So far, lock-in between the cavity and the distributed elastic resonator has not been achieved. Further investigations to determine the role of the source and resonator attributes are underway.

AB - At low flow Mach numbers, fluid-elastic lock-in may occur when a shear layer instability interacts with an adjoining or nearby structure and the resulting vibration of the structure reinforces the shear layer instability. Despite the significant amount of study of lock-in with acoustic resonators, fluid-elastic lock-in of a shear layer fluctuation over a cavity and a structural resonator is not well understood and has not been thoroughly studied. Design of an experimental system is described and preliminary diagnostics are addressed as a basis for a platform for developing a fundamental understanding of the feedback mechanism, analytical models for predicting and describing fluid-elastic lock-in conditions, and the roles of the fluid and structural dynamics in the process. Features of the system investigated here include design for characterization of modal excitation of a beam-like structure from the shear layer fluctuation, isolation of the predominant instability source to the shear layer fluctuation over the cavity, variation of the cavity size to identify critical parameters that govern fluidelastic lock-in, and alteration of the inflow boundary layer momentum thickness. So far, lock-in between the cavity and the distributed elastic resonator has not been achieved. Further investigations to determine the role of the source and resonator attributes are underway.

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Cody KLF, Hambric SA, Pollack ML. Challenges of investigating fluid-elastic lock-in of a shallow cavity and a cantilevered beam at low mach numbers. In American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA. 2005. p. 253-261. (American Society of Mechanical Engineers, Noise Control and Acoustics Division (Publication) NCA). https://doi.org/10.1115/IMECE2005-79162