International Journal of Aeroacoustics最新文献_第9页

Boundary element analysis on the fuselage scattering of drone noise 无人机机身噪声散射的边界元分析

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2022-02-26 DOI: 10.1177/1475472X221079549

Hanbo Jiang, Siyang Zhong, Xin Zhang, Xun Huang

引用次数: 1

Application of LES combined with a wave equation for the simulation of noise induced by a flow past a generic side mirror 应用LES结合波动方程模拟流过一般侧镜所引起的噪声

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2022-02-23 DOI: 10.1177/1475472X221079542

E. Guseva, Y. Egorov

{"title":"Application of LES combined with a wave equation for the simulation of noise induced by a flow past a generic side mirror","authors":"E. Guseva, Y. Egorov","doi":"10.1177/1475472X221079542","DOIUrl":"https://doi.org/10.1177/1475472X221079542","url":null,"abstract":"The paper presents validation results of a hybrid simulation method for aeroacoustics in turbulent flows at low Mach numbers. The hybrid method implemented in the Ansys Fluent® CFD package applies a scale-resolving turbulence model to compute the noise sources in an incompressible flow, while the noise propagation is modeled by a wave equation formulated for the acoustic potential. The selected test case deals with a flow and a sound field around a generic side view mirror of a car. The SBES model by Menter, which belongs to the class of the RANS-LES models, is used for the flow simulation. It switches to the Large Eddy Simulation (LES) mode in separated mixing layers and recirculation zone behind the mirror as well as in the following wake, where flow develops intensive turbulence and dominating noise sources. The acoustics wave equation is formulated in the model form of Kaltenbacher et al. and is applied in the time domain. The overall calculation is performed as a transient co-simulation on the same mesh using the finite-volume discretization method for both the flow and the acoustics parts. The wave equation is advanced in time using the HHT-α method. Obtained distribution of the mean wall pressure over the mirror surface closely matches the experimental one. Rich content of the resolved turbulent vortices in the separation zone and good agreement of the calculated and measured wall pressure spectra at sensor locations downstream the mirror evidence a proper LES resolution quality of noise sources. Comparison of the computed noise spectra at the remote microphones with the experimental data demonstrates the sound propagation accuracy and validates the overall aeroacoustics simulation method.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"6 - 21"},"PeriodicalIF":1.0,"publicationDate":"2022-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46966149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fundamental investigation using active plasma control to reduce blade–vortex interaction noise 利用主动等离子体控制降低叶片-涡流相互作用噪声的基础研究

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-11-01 DOI: 10.1177/1475472X211052699

T. Patel, Alexander J. Lilley, Weiqi Shen, Christian Porrello, A. Schindler-Tyka, Subrata Roy, W. Lear, Steven A. E. Miller

引用次数: 4

Guest editor biographies 特邀编辑传记

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-11-01 DOI: 10.1177/1475472x211061782

引用次数: 0

Further assessment of a time domain impedance boundary condition for the numerical simulation of noise-absorbing materials 吸声材料数值模拟的时域阻抗边界条件的进一步评估

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-11-01 DOI: 10.1177/1475472X211052701

S. Redonnet

{"title":"Further assessment of a time domain impedance boundary condition for the numerical simulation of noise-absorbing materials","authors":"S. Redonnet","doi":"10.1177/1475472X211052701","DOIUrl":"https://doi.org/10.1177/1475472X211052701","url":null,"abstract":"In regard to the mitigation of environmental noise across major industry sectors, the present study focuses on the numerical prediction of passive noise reduction devices. Here, it is further explored how the noise attenuation induced by locally reacting noise absorbing materials (also called acoustic liners) can be simulated using a time domain highly accurate Computational AeroAcoustics (CAA) method. To this end, it is assessed how a classical Time Domain Impedance Boundary Condition (TDIBC) can effectively model acoustic liners of practical interest, including when the latter are exposed to realistic conditions (grazing flow and noise excitation). The investigation consists in numerically reproducing two experimental campaigns initially performed at NASA Langley Research Center. Two different materials are considered (honeycomb superimposed with perforate or wiremesh resistive face-sheet), each being characterized by a specific noise attenuation behaviour (e.g. dependency on the flow conditions and/or noise excitation). Each material is tested under various flow conditions (e.g. grazing flow of Mach up to 0.5) and/or noise source excitation (e.g. multiple tones of level up to 140 dB each). The results demonstrate the ability of the underlying CAA/TDIBC approach to simulate realistic acoustic liners in non-trivial configurations, with enough physical accuracy (e.g. correct capture of the noise attenuation characteristics) and numerical robustness (e.g. absence of instabilities). The study also reveals that, independent from the CAA/TDIBC approach itself, some specific pre-processing tasks (e.g. impedance eduction and subsequent TDIBC calibration) may play a bigger role than expected, in practice.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"20 1","pages":"927 - 958"},"PeriodicalIF":1.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44752261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effect of a pylon on the broadband noise sources of counter-rotating turbomachinery 挂架对反向旋转涡轮机械宽带噪声源的影响

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-11-01 DOI: 10.1177/1475472X211055178

Kristóf Tokaji, Csaba Horváth

{"title":"Effect of a pylon on the broadband noise sources of counter-rotating turbomachinery","authors":"Kristóf Tokaji, Csaba Horváth","doi":"10.1177/1475472X211055178","DOIUrl":"https://doi.org/10.1177/1475472X211055178","url":null,"abstract":"Pylons are commonly used for the mounting of engines in the aircraft industry. On the other hand, the installation of a pylon influences the noise generation mechanisms and therefore alters the broadband noise characteristics of a given turbomachinery setup. In this investigation, a counter-rotating open rotor with and without a pylon is investigated in order to determine its effects on broadband noise sources. The various broadband noise sources and their typical frequency ranges have been determined using beamforming maps and spectral analysis. In order to attain a clear impression regarding the broadband noise sources, the Double Filtering beamforming method has been utilized in the investigation. This method removes the tonal components from the recorded signal of a microphone array, resulting in a purely broadband signal. Using beamforming maps, the dominant broadband noise source amplitudes and locations can therefore be investigated in great detail. Compared to other methods, the investigation of measurement data and beamforming maps helps determine the amplitude, the frequency range, and the significance of the various types of broadband noise sources that are truly present in the emitted noise. It has been found for lower frequencies, that the broadband noise sources at the blade root of the aft rotor are dominant, while for higher frequencies, the significant broadband noise sources are localized to the trailing edge region of the forward rotor and the leading edge of the aft rotor. The installation of a pylon has resulted in an additional broadband noise source appearing at the blade tip of the aft rotor.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"20 1","pages":"979 - 1002"},"PeriodicalIF":1.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49468025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Aeroacoustic noise prediction of a vertical axis wind turbine using large eddy simulation 基于大涡模拟的垂直轴风力发电机气动噪声预测

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-11-01 DOI: 10.1177/1475472X211055179

A. Aihara, K. Bolin, A. Goude, H. Bernhoff

{"title":"Aeroacoustic noise prediction of a vertical axis wind turbine using large eddy simulation","authors":"A. Aihara, K. Bolin, A. Goude, H. Bernhoff","doi":"10.1177/1475472X211055179","DOIUrl":"https://doi.org/10.1177/1475472X211055179","url":null,"abstract":"This study investigates the numerical prediction for the aerodynamic noise of the vertical axis wind turbine using large eddy simulation and the acoustic analogy. Low noise designs are required especially in residential areas, and sound level generated by the wind turbine is therefore important to estimate. In this paper, the incompressible flow field around the 12 kW straight-bladed vertical axis wind turbine with the rotor diameter of 6.5 m is solved, and the sound propagation is calculated based on the Ffowcs Williams and Hawkings acoustic analogy. The sound pressure for the turbine operating at high tip speed ratio is predicted, and it is validated by comparing with measurement. The measured spectra of the sound pressure observed at several azimuth angles show the broadband characteristics, and the prediction is able to reproduce the shape of these spectra. While previous works studying small-scaled vertical axis wind turbines found that the thickness noise is the dominant sound source, the loading noise can be considered to be a main contribution to the total sound for this turbine. The simulation also indicates that the received noise level is higher when the blade moves in the downwind than in the upwind side.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"20 1","pages":"959 - 978"},"PeriodicalIF":1.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49043830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Editorial for special issue on acoustic liners 声学衬垫特刊社论

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-09-01 DOI: 10.1177/1475472X211042204

D. Sutliff

{"title":"Editorial for special issue on acoustic liners","authors":"D. Sutliff","doi":"10.1177/1475472X211042204","DOIUrl":"https://doi.org/10.1177/1475472X211042204","url":null,"abstract":"I am honored to present to the readers this special issue of the International Journal of Aeroacoustics on Acoustic Liners. Acoustic Liners have been studied since the introduction of turbojet engines and implemented shortly thereafter. Currently, almost all commercial turbofan engines nacelles have acoustic liners installed in somemanner. This Special Issue onAcoustic Liners provides 16 papers across a breadth of material – from analytical and numerical modelling to unique test rigs to evaluation of liner concepts. Contributors from academia, government agencies, and industry throughout the international community provide a range of insight. The focus is on the tried-and-true passive liner paradigmwhich continues to be the principal method of achieving noise reduction. The passive liner concept is straightforward – however, higher bypass ratios and shorter engine nacelles in advanced turbofans, as well as continuing demand for increased noise reduction while mitigating any performance impact, necessitates a continual improvement in liner acoustic performance and installation in novel locations. Therefore, continued study by the aeroacoustics community in this area is necessary to maintain our critical contribution to the improvement of the quality of life in communities near airports. I thank the authors for their contributions whose creativity and expertise are the basis of this issue. I sincerely appreciate the reviewers for their time spent in reviews and providing feedback which greatly improved the quality of the papers. I am grateful to the Editor-in-chief, Dr Ganesh Raman, and the International Journal of Aeroacoustics for providing an opportunity for publishing this special issue. In addition, my thanks are extended to Dr Ed Envia, Assistant Editor, who handled the papers for which I was an author.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"20 1","pages":"440 - 440"},"PeriodicalIF":1.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65854651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

SwirlProp: A tool for sound propagation and attenuation in swirling flows SwillProp：一种用于涡流中声音传播和衰减的工具

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-09-01 DOI: 10.1177/1475472x211052591

A. L. Maldonado, R. Astley

{"title":"SwirlProp: A tool for sound propagation and attenuation in swirling flows","authors":"A. L. Maldonado, R. Astley","doi":"10.1177/1475472x211052591","DOIUrl":"https://doi.org/10.1177/1475472x211052591","url":null,"abstract":"The current trends for next generation turbofan engines are towards shorter nacelles and increased distances between the fan and the outlet guide vanes. This leads to an overall reduction in lined surface areas as well as an increase in the relative importance of the interstage liner, which is the liner placed between the rotor blades and the stator vanes. So far most of the efforts have been on liners for intakes and bypass ducts. The interstage is different in that the liner is subject to a mean flow with a strong swirl component and shear. The SwirlProp code was developed to contribute to understanding and predicting the effect of the swirl on liner attenuation. The code is based on the linearized Euler equations together with the Ingard–Myers boundary condition. An eigenvalue problem is formulated and discretized using a finite difference method. The code is exhaustively compared against predicted values obtained by other methods for uniform, sheared and swirling mean flows and hard-walled and lined ducts. A cross-validation between SwirlProp and an in-house code from Rolls-Royce was carried out for a more realistic case. Also, details on the implementation of the boundary condition are proposed and details are presented.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"20 1","pages":"588 - 609"},"PeriodicalIF":1.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49459862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Swirling mean flow effects on locally reacting interstage liner 旋流平均流量对局部反应级间衬管的影响

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2021-09-01 DOI: 10.1177/1475472X211043339

Vianney Masson, S. Moreau, H. Posson, Thomas Nodé-Langlois

{"title":"Swirling mean flow effects on locally reacting interstage liner","authors":"Vianney Masson, S. Moreau, H. Posson, Thomas Nodé-Langlois","doi":"10.1177/1475472X211043339","DOIUrl":"https://doi.org/10.1177/1475472X211043339","url":null,"abstract":"Sound transmission through a finite-lined section in a rigid annular duct with swirling and sheared mean flow is analyzed with a new mode-matching method based on the conservation of the total enthalpy and the mass flow, which does not reduce to the conservation of the pressure and the axial velocity when the swirl is non-zero. It relies on a new projection method based on the property of the Chebyshev polynomials and on the scattering matrix formalism to yield transmission losses. This new method is first validated against a finite elements method tool in the uniform axial flow case, and then provides a parametric study of the effect of swirl. At low azimuthal mode order m , the swirl amplifies the attenuation of the contra-rotating modes and makes the attenuation of the co-rotating modes decrease with a trend of a general shift of the transmission loss curve toward contra-rotating modes. A small rotation of the transmission loss curves at low | m | is also generally observed. The boundary condition in the lined section has a small effect on the transmission loss, except close to the cut-on thresholds. Finally, the duct boundary-layer thickness has a significant effect on the cut-on modes and the transmission loss but not its profile.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"20 1","pages":"561 - 587"},"PeriodicalIF":1.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47604355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0