Low-wavenumber turbulent boundary layer wall-pressure measurements from vibration data on a cylinder in pipe flow

Bonness, William K.; Capone, Dean E.; Hambric, Stephen A.

doi:10.1016/j.jsv.2010.04.010

Cited by 38 publications

(26 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The squared magnitude of the spatial Fourier transform of the mode shape function of a structure is usually called the wavenumber sensitivity function or wavenumber filter shape function, and is often used to calculate the coupling between exciting pressure fields and mode shapes for rectangular panels [1][2][3][4] and cylinders, 5,6 both under fluctuating wall pressure excitations. It can be also used to calculate the radiation efficiency of rectangular panels in the wavenumber domain.…”

Section: Introductionmentioning

confidence: 99%

Experimental evidence of modal wavenumber relation to zeros in the wavenumber spectrum of a simply supported plate

Robin

Berry

Atalla

et al. 2015

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental evidence of modal wavenumber relation to zeros in the wavenumber spectrum of a simply supported plate

Robin

Berry

Atalla

et al. 2015

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

show abstract

“…The conditioned spectral density noise removal technique is illustrated using data obtained by Bonness, Capone, and Hambric [4]. They measured cylinder vibrations and TBL dynamic wall pressures from a thin-walled 0.15 m diameter aluminum cylinder internally filled with water (pipe-flow) flowing at 6.1 m/s.…”

Section: Measured Datamentioning

confidence: 99%

Removing Unwanted Noise from Operational Modal Analysis Data

Bonness

Jenkins

2015

Topics in Modal Analysis, Volume 10

Self Cite

View full text Add to dashboard Cite

Operational modal analysis data includes the measurement of dynamic signals such as structural vibration data and the corresponding excitation force or pressure. In addition to the desired information, measured structural vibration data can include unwanted electrical noise and vibration energy from adjacent structures. Measured dynamic pressures can contain unwanted signals such as acoustic and vibration induced pressures. In this paper, a noise removal technique is presented in which an unlimited number of unwanted correlated signals can be removed from a set of measured data. In its simplest form, this technique is related to coherent output power (COP). However, unlike COP noise removal, multiple signals can be removed from measured data while retaining the magnitude and phase of the original data required for modal analysis processing. This technique is demonstrated using vibration data and dynamic wall pressure measurements from a thin-walled aluminum cylinder filled with water flowing at 20 ft/s. IntroductionOperational modal analysis involves measuring the vibration of a system during operation either because the desired operational excitation is not appropriately represented by traditional impulsive modal impact testing or because the system cannot be conveniently taken off-line. Transfer function data between vibration and input force are traditionally measured and used as input for an experimental modal analysis. However, when the input force cannot be measured, cross-spectrum measurements between accelerometers can be used in place of the transfer function data. Resonance frequency, damping, and operational modes shapes can all be obtained from cross-spectrum measurements between accelerometers placed at locations required to appropriately resolve the structural mode shapes. Occasionally, measurements of dynamic force or pressure can also be made to help determine modal mass.Measurements of structural vibration or pressure often include unwanted signals not associated with the signals of interest -especially in an operational setting where other machinery or processes are often running. The unwanted signals may be associated with electrical noise, vibration energy from adjacent structures, vibration induced pressures, and acoustic pressures. While various noise removal techniques are available to "clean up" measured data, a conditioned spectral density technique [1] is presented which can remove multiple signals of unwanted noise from measurements of cross-spectra. This technique can be applied to any dynamic signal measurements which meet necessary criteria.Lauchle and Daniels [2] employed a related subtraction technique using multiple sensors measured simultaneously to remove noise signals from their measurements of turbulent boundary layer (TBL) wall pressure. Naguib, Gravante, and Wark [3] discuss the advantages of an optimal filtering approach compared to a difference approach. In their work, the optimal filtering provides a better estimate of the noise than the difference approach. The ...

show abstract

“…The parameters characterizing the turbulent boundary layer are supposed to be known: U  is the flow velocity, c U , the convection velocity, δ is the boundary layer thickness, and w  the wall shear stress. From these parameters and the wall pressure models proposed in the literature [2][3][4][5], we can define the spectrum of the wall pressure fluctuations acting on the plate. The auto spectrum density of the wall pressure   pp S  is evaluated here considering Goody's model [8] whereas the normalised cross spectrum density is evaluated using the Corcos's model [2].…”

Section: Presentation Of the Problemmentioning

confidence: 99%

“…2 -The spectrum of the wall pressure fluctuations is evaluated from the TBL parameters estimated in the previous step and by using one of the models proposed in the literature. Some of them are expressed in the space -frequency domain (like the famous Corcos model [1]) whereas as others are expressed in the wavenumber -frequency domain (like the no less famous Chase model [2]); Discussion about different models and comparison with experiment can be found in [3,4] for the frequency auto spectrum and in [5,6] for the normalized wavenumber cross spectrum;…”

Section: Introductionmentioning

confidence: 99%

Discussion About Different Methods for Introducing the Turbulent Boundary Layer Excitation in Vibroacoustic Models

Maxit

Berton

Audoly³

et al. 2014

Flinovia - Flow Induced Noise and Vibration Issues and Aspects

View full text Add to dashboard Cite

For controlling the noise radiated from vibrating structures excited by turbulent boundary layer (TBL) it is relevant to develop numerical tools for understanding how the structure reacts to TBL excitation. Usually, the wall pressure fluctuations of the TBL are described through statistical quantities (i.e. space-frequency or wavenumber-frequency spectra) which depend on the TBL parameters. On the other hand, the vibro-acoustic models (i.e. Finite Elements, Boundary Elements, Transfer Matrix Methods, Analytical models, etc) evaluate deterministic transfer functions which characterise the response of the considered structures. The first part of this paper focuses on the coupling between the stochastic TBL and the deterministic vibro-acoustic models. Five techniques are presented. Numerical applications on an academic marine test case are proposed in order to discuss the calculation parameters and the interests / drawbacks of each technique. In the second part of the paper, the high frequency modelling with the Statistical Energy Analysis (SEA) method is considered. The focus is placed on the estimation of an important input of this method: the injected power by the TBL into the structure for each third octave band.

show abstract

Low-wavenumber turbulent boundary layer wall-pressure measurements from vibration data on a cylinder in pipe flow

Cited by 38 publications

References 29 publications

Experimental evidence of modal wavenumber relation to zeros in the wavenumber spectrum of a simply supported plate

Experimental evidence of modal wavenumber relation to zeros in the wavenumber spectrum of a simply supported plate

Removing Unwanted Noise from Operational Modal Analysis Data

Discussion About Different Methods for Introducing the Turbulent Boundary Layer Excitation in Vibroacoustic Models

Contact Info

Product

Resources

About