Boundary Layer Induced Noise in Aircraft, Part I: The Flat Plate Model

Graham, W. R. M.

doi:10.1006/jsvi.1996.0178

Cited by 103 publications

(53 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The correlation length is a measure of the extent of spatially coherent power in the wall pressure and is thus an important parameter in studies of structural response to boundary layer excitation [1][2][3]. The nature of the boundary layer is particularly important to studies of aircraft interior noise where the boundary layer is the dominant noise source.…”

Section: Introductionmentioning

confidence: 99%

“…The models also assume that the wall pressure statistics are homogeneous and stationary [6,9], that is, the wall pressure can be considered to be a single process and statistical quantities such as the power spectrum and cross spectrum are constant over the space/time dimensions of the analyses. Assuming stationarity, the cross spectrum can be derived by scaling the power spectrum according to a coherence length 1 and adjusting the phase according to the convection wavenumber. This is the basis of the Corcos model [6].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Determining correlation and coherence lengths in turbulent boundary layer flight data

Palumbo

2012

Journal of Sound and Vibration

View full text Add to dashboard Cite

a b s t r a c tWall pressure data acquired during flight tests at several flight conditions are analysed and the correlation and coherence lengths of the data reported. It is found that the correlation and coherence lengths are influenced by the origin of the structure producing the pressure and the frequency bandwidth over which the analyses are performed. It is shown how the frequency bandwidth biases the correlation length and how the convection of the pressure field might reduce the coherence measured between sensors. A convected form of the cross correlation and cross spectrum is introduced to compensate for the effects of convection. Coherence lengths measured in the streamwise direction appear much longer than expected. Coherent structures detected using the convected cross correlation do not exhibit an exponential coherent power decay.Published by Elsevier Ltd.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determining correlation and coherence lengths in turbulent boundary layer flight data

Palumbo

2012

Journal of Sound and Vibration

View full text Add to dashboard Cite

show abstract

“…Davis [13] proposed a space integration method including the light fluid loading effect to estimate the power density functions of the displacement of the finite plate and of the radiated acoustic pressure. Graham [14] reviewed statistical models of the boundary layer and investigated the more specific case of aircraft statistical models of TBL. 70…”

Section: Models) Discussion On Different Models Andmentioning

confidence: 99%

“…(17) when the wave amplitudes are defined by Eq. (14). The CSD function of the WPF corresponding to an infinite number of realizations is then equal to the CSD function of the TBL excitation.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Simulation of the pressure field beneath a turbulent boundary layer using realizations of uncorrelated wall plane waves

Maxit

2016

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

This paper investigates the modelling of a vibrating structure excited by a turbulent boundary 15 layer (TBL). Although the wall pressure field (WPF) of the TBL constitute a random excitation, the element-based methods generally used for describing complex mechanical structures consider deterministic loads. The response of the structure to a random excitation like TBL is generally deduced from calculations of numerous Frequency Response Functions. The result is that the process requires costly computational resources. To tackle this issue, an efficient 20 process is proposed for generating realizations of the WPF corresponding to the TBL. This process is based on a formulation of the problem in the wave-number space and the interpretation of the wall pressure field as uncorrelated wall plane waves. Once the WPF have been synthesized, the local vibroacoustic responses are calculated for the different realizations and averaged together in the last step. A numerical application of this process to a plate beneath 25 a TBL is used to verify its efficiency and ability to reproduce the partial space correlation of the excitation. Finally an application on a stiffened panel modelled with the finite element method is proposed to illustrate the interest of the proposed process.Running title: Numerical synthesis of random pressure field 30

show abstract

Interior Noise and Sound Transmission

Neple

2010

Encyclopedia of Aerospace Engineering

View full text Add to dashboard Cite

Aircraft interior noise control as a major factor of cabin and cockpit comfort is considered as an essential design requirement by transport airplane manufacturers. External sources such as the turbulent boundary layer excitation and acoustic radiation from engines being the main interior noise contributors over a large frequency range, this section focuses mainly on sound transmission through fuselage structure and noise control treatments. After describing the existing noise sources and the main characteristics of a fuselage structure including classical noise control treatments, the emphasis will be put on the methodology to assess interior noise, based on typical testing and existing modeling methods. The complexity of the fluid‐structure coupled issue and the main weak and strong points of each modeling method, both at aircraft and fuselage element level, will be addressed. Then, understanding and modeling the vibroacoustic behavior of stiffened structures being necessary to assess overall interior noise level, a dedicated section will describe the main phenomena governing sound transmission through these elements. Finally, the excitation field effect on sound transmission mechanisms and particularly on noise control treatments efficiency will be discussed. Turbulent boundary layer, diffuse sound field, and structure‐borne excitation will be considered.

show abstract

Boundary Layer Induced Noise in Aircraft, Part I: The Flat Plate Model

Cited by 103 publications

References 1 publication

Determining correlation and coherence lengths in turbulent boundary layer flight data

Determining correlation and coherence lengths in turbulent boundary layer flight data

Simulation of the pressure field beneath a turbulent boundary layer using realizations of uncorrelated wall plane waves

Interior Noise and Sound Transmission

Contact Info

Product

Resources

About