{"title":"Effect of 2D ice accretion on turbulent boundary layer and trailing-edge noise","authors":"Hyunjune Gill, Seongkyu Lee","doi":"10.1177/1475472X221099497","DOIUrl":"https://doi.org/10.1177/1475472X221099497","url":null,"abstract":"Trailing-edge noise is known to be sensitive to airfoil shapes, and ice accretion is one cause of an airfoil shape deformation. This paper investigates how trailing-edge noise is affected by the airfoil shape deformation due to ice accretion. The formation of ice-induced flow separation and the development of a turbulent boundary layer are analyzed to understand the correlation between the altered flow physics due to ice accretion inside the boundary layer and trailing-edge noise. The near-wall flow behind the leading-edge ice accretion is analyzed by using Reynolds-Averaged Navier Stokes CFD in OpenFOAM, and trailing-edge noise is investigated using an empirical wall pressure spectrum model in conjunction with Amiet’s trailing-edge noise theory. Validations of tools against measurement data are presented. Liquid water content, freestream velocity, and ambient temperature are varied to investigate the impact of flow conditions on the ice accretion shape and the resulting boundary layer flow characteristics at the trailing edge. It is found that a more significant leading edge deformation due to ice accretion generates larger ice-induced flow separation bubbles, which increases the trailing-edge boundary layer thickness. As a result, an increase in low- and mid-frequency noise is observed. The purpose of this paper is not only to understand the effect of ice accretion on trailing-edge noise but also to comprehensively analyze how flow physics inside the turbulent boundary layer is altered by the presence of various ice accretion shapes.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"260 - 285"},"PeriodicalIF":1.0,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42876181","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}
{"title":"A study on an integrated aero-vibro-acoustic analysis procedure for a small-scale supersonic jet and surrounding thin plates","authors":"H. Joo, T. Park, Seung-Hoon Kang, S. Shin, W. Ohm","doi":"10.1177/1475472X221093702","DOIUrl":"https://doi.org/10.1177/1475472X221093702","url":null,"abstract":"The goal of this paper is to examine the computational approaches for predicting both of the overall sound pressure level (OASPL) at a few locations and acceleration power spectral density (APSD) of surrounding thin plates due to the aero-acoustic pressure generated by a cold jet with M = 1.8. First, computational fluid dynamics (CFD), particularly delayed detached eddy simulation, are applied to predict the OASPL at the near-field and compute the acoustic properties. Second, the linearized boundary element method (BEM), that is, the Helmholtz-Kirchhoff method is utilized to propagate the pressure and obtain the OASPL at the far-field. Finally, the finite element method is implemented to predict the APSD for a clamped thin plate based on the optimal triangle membrane element, discrete Kirchhoff triangle plate bending element, and Newmark-β time integration scheme. Using the present CFD and BEM, the OASPLs are compared with the experimental results measured by microphones at both the near- and far-fields, respectively. Moreover, APSDs are compared with the experimental results obtained by an accelerometer at a few different locations. Although OASPLs are overestimated because of the coarse meshes in the higher-angle area and low order scheme of the present CFD analysis, the present integrated aero-vibro-acoustic analysis is capable of predicting the OASPL and APSD generated by a cold jet with M = 1.8.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"115 - 141"},"PeriodicalIF":1.0,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48351495","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}
{"title":"Flow-noise characteristics of turbocharger compressors with rotational balance cuttings","authors":"Sang Hyun Kim, T. Park","doi":"10.1177/1475472X221093707","DOIUrl":"https://doi.org/10.1177/1475472X221093707","url":null,"abstract":"To correct the balance of the rotating assembly of a turbocharger, some parts of the compressor wheel are removed by cutting. A numerical investigation of the turbulent flows and flow noises produced by compressor wheels modified with such cutting parts was performed by a turbulence model and detached-eddy simulations. For the 6-cutting case, 0, 2, 4, and 6 circular cuttings and two additional—rectangular and triangular—shapes were used. To investigate the effects of the balance cuttings in a compressor wheel, the evaluation process using computational fluid dynamics was tried. It was found that the fluid forces due to the various wheel shapes have the potential to restore the eccentricity by approximately 50%. Severe variations of velocity, pressure, and turbulent kinetic energy in the interspace between the wheel and volute were observed. In particular, the wavelike patterns of pressure and turbulent kinetic energy were intensified for the modified wheels. The turbulent kinetic energy of the 6-cutting case had a dominant frequency at approximately 3000 Hz. The spectrum of the sound-pressure level of the modified compressor wheels exhibited the features of buzz-saw noise. The flow fields suggested that this feature of the sound pressure is related to the tip-clearance flow affected by the balance cuttings. In addition, the acoustic pressure and flow characteristics of the different types of modified compressor wheels were discussed and the resulting acoustic power was evaluated.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"190 - 217"},"PeriodicalIF":1.0,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47314722","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}
{"title":"An improved algorithm for liner impedance eduction in low signal-to-noise ratio flow duct","authors":"Penglin Zhang, Cheng Yang, Yu Huang","doi":"10.1177/1475472X221093710","DOIUrl":"https://doi.org/10.1177/1475472X221093710","url":null,"abstract":"The impedance eduction technique is widely used by the aeroacoustics community to obtain liner property in a flow duct. However, the obtained impedance is often found to be discontinuous in the frequency domain which violates theoretical liner models. The low signal-to-noise ratio (SNR, in dB) is one factor leading to this unexpected result. To overcome this, a weighting coefficient, represented by an SNR dependent sigmoid function with two control parameters, is introduced to the cost function in the iteration process. The proposed algorithm is employed to measure the impedances of two liners and results show an improvement in the smoothness of the resultant impedance curves over those obtained from conventional cost function.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"168 - 189"},"PeriodicalIF":1.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48423359","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}
{"title":"A fast 3D-MUSIC method for near-field sound source localization based on the bat algorithm","authors":"C. Yang, LL Sun, H. Guo, Y.S. Wang, Y. Shao","doi":"10.1177/1475472X221093711","DOIUrl":"https://doi.org/10.1177/1475472X221093711","url":null,"abstract":"To improve the computation and real-time performances of the multiple signal classification (MUSIC) algorithm in 3D space, a fast sound source localization method based on the bat algorithm (BA) and the 3D-MUSIC, called BA-based 3D-MUSIC algorithm (3D-BMUSIC), is presented in this paper. 3D-BMUSIC greatly reduces the computation load by replacing the regular grid search with the BA. First, the near-field spherical wave model is established to obtain the spectral function of the 3D-MUSIC. Then, the spectral function is defined as the fitness function, which calculates the fitness value corresponding to each bat position. Finally, the global optimal bat position with the largest fitness value, as sound source localization, is obtained by successive iteration and sorting. The simulation and experiment show that 3D-BMUSIC accurately estimates the DOA and distance of near-field sources, and the root-mean-square error (RMSE) of 3D-BMUSIC is less than that of 3D-MUSIC. In addition, 3D-BMUSIC effectively reduces the computation time by approximately 96–98%. With shorter computation time and higher efficiency, 3D-BMUSIC promotes hardware implementation and is more suitable for high-precision localization of near-field sound sources.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"98 - 114"},"PeriodicalIF":1.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43521341","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}
Wei Ying, R. Fattah, Sinforiano Cantos, Siyang Zhong, Tatiana Kozubskaya
{"title":"Computational aeroacoustics of aerofoil leading edge noise using the volume penalization-based immersed boundary methods","authors":"Wei Ying, R. Fattah, Sinforiano Cantos, Siyang Zhong, Tatiana Kozubskaya","doi":"10.1177/1475472X221079557","DOIUrl":"https://doi.org/10.1177/1475472X221079557","url":null,"abstract":"Broadband noise due to the turbulence-aerofoil interaction, which is also called the leading edge noise, is one of the major noise sources of aircraft (including the engine). To study the noise properties numerically is a popular approach with the increasing power of computers. Conventional approaches of using body-fitted grids at the boundaries would be convoluted due to the complex geometries, which can constrain the efficiency of parametric studies. A promising approach to tackle this issue is to use the immersed boundary method (IBM). Among various IBM variants, the volume penalization (VP) approach employs a masking function to identify the immersed solid boundary, and continuous forcing terms are added to the original flow governing equations to account for the boundary conditions. It is, therefore, efficient and easy to implement into the existing computational aeroacoustics solvers. In this work, the VP-based IBM is used to simulate the leading edge noise by combining with the advanced synthetic turbulence method. The simulations are conducted for both the isolated aerofoils and cascade, and the results are compared with the well-validated body-fitted grid solutions. The viscosity effect is also highlighted by comparing the results obtained by solving both Euler and Navier–Stokes equations.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"74 - 94"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42544279","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}
{"title":"Editorial","authors":"Tatiana Kozubskaya","doi":"10.1177/1475472X221087007","DOIUrl":"https://doi.org/10.1177/1475472X221087007","url":null,"abstract":"work concerning the investigation of noise shielding of a de fl ected fl ap. They propose an original approach to provide a reasonable agreement between the numerical data obtained using the boundary element method and the results of fl yover mea-surements with a lack of input data. The most innovative computational techniques in my opinion are presented in the paper of the researchers from Roma Tre University with Lorenzo Burghignoli as a corresponding author. They develop adaptive metamodels based on radial basis functions to be used in the design optimization process for unconventional aircraft layouts. The fi fth paper prepared by Ekaterina Guseva from St-Petersburg Polytechnical University and Yuri Egorov from ANSYS Germany study the noise induced by a fl ow past a car side mirror. For this purpose, they developed a hybrid method for simulating aeroacoustics of turbulent fl ows at low Mach numbers and implemented it in the Ansys Fluent CFD package. I hope you will enjoy reading all presented papers in detail.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"4 - 5"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43299792","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}
{"title":"Noise shielding of a deflected flap for comparing numerical predictions with flyover experiments","authors":"M. Mößner, J. Delfs, M. Pott-Pollenske","doi":"10.1177/1475472X221079560","DOIUrl":"https://doi.org/10.1177/1475472X221079560","url":null,"abstract":"Comparing acoustic simulations against experimental data is an essential step in order to prove the correctness of numerical tools. This can be done with wind tunnel experiments where the environmental conditions can be adjusted very accurately. Ultimately, the tools must be capable of predicting real-word scenarios like aircraft flyovers. However, obtaining precise data from flyover experiments is challenging and often important input data is missing. The current paper shows, that by extracting the shielding effect of a small detail, a deflecting flap of an aircraft with rear-mounted engines, it is possible to reproduce flyover measurements with a boundary element method, even when only little engine information is known. The boundary element method can only take a constant mean flow into account, but by additionally evaluating results of a volume-resolved discontinuous Galerkin method more insights into the expected effects of a realistic mean flow is given.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"57 - 73"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46299496","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}
L. Burghignoli, Monica Rossetti, F. Centracchio, Giorgio Palma, U. Iemma
{"title":"Adaptive RBF with hyperparameter optimisation for aeroacoustic applications","authors":"L. Burghignoli, Monica Rossetti, F. Centracchio, Giorgio Palma, U. Iemma","doi":"10.1177/1475472X221079545","DOIUrl":"https://doi.org/10.1177/1475472X221079545","url":null,"abstract":"The present work reports an investigation on the use of adaptive metamodels based on radial basis functions (RBFs) for aeroacoustic applications of highly innovative configurations. The relevance of the topic lies on the paramount importance of metamodelling techniques within the design optimisation process of disruptive aircraft layouts. Indeed, the air traffic growth, consequently the hard environmental constraints imposed by regulations, will make a technological breakthrough, an imperative need within few years. As a consequence, the engineering community is paying particular attention to the development of innovative techniques for the design of unconventional configurations. For this class of applications, the designer cannot successfully rely on historical data or low-fidelity models, and the expensive direct simulations remain the only valuable design strategy. In this regard, it can be demonstrated that the use of surrogate models, i.e., metamodels, significantly reduces the computing costs, especially in view of a robust approach to the optimised design. In order to further improve the efficiency of metamodel-based techniques, dynamic approaches based on hyperparameter optimisation and adaptive sampling procedures have been recently developed. The case study presented here pertains the exploiting of dynamic RBF-based metamodels for noise shielding applications. The analysis of the metamodel performances and its convergence properties shows how the final number of direct simulations is significantly reduced by the hyperparameter optimisation algorithm, still strongly depending on the choice of the RBF kernel function.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":"21 1","pages":"22 - 42"},"PeriodicalIF":1.0,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45315565","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}