J. Morgan, Christopher Shoemaker, D. K. Mclaughlin, P. Morris, Z. Berger
{"title":"Analysis of Fluid Insert Noise Reduction Method with PIV","authors":"J. Morgan, Christopher Shoemaker, D. K. Mclaughlin, P. Morris, Z. Berger","doi":"10.2514/6.2018-3610","DOIUrl":"https://doi.org/10.2514/6.2018-3610","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"98 1-3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114026126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of rounded corners on the flow and noise from a cube","authors":"Yanan Wang, David J. Thompson, Zhiwei Hu","doi":"10.2514/6.2018-2960","DOIUrl":"https://doi.org/10.2514/6.2018-2960","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114305949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Kolkman, L. D. Santana, A. V. Garrel, C. Venner, Arlos Arce León, M. Sanders
The wind energy industry is progressively aiming towards larger wind turbine size as a means of increasing energy production efficiency. Wind turbine rotor blades are becoming significantly more flexible and have an increased risk of structural failure. Thicker airfoil profiles can be used to increase the structural strength. However, thicker airfoils are more prone to flow separation with adverse effect on power generation. Vortex generators (VGs) are an effective solution to delay flow separation. However, VGs significantly increase radiated noise levels. This presented research experimentally investigates the effect of VGs on blade noise production. Specifically, the influence of the VG geometric shape is evaluated while keeping the dimensions constant. Wind tunnel tests have been carried out on a NACA 0018 that is equipped with triangular vane-type VGs specifically designed for the test conditions. A microphone phased array is used to assess the radiated noise using the beamforming technique. The results show that the VGs significantly contribute to increase the blade noise production with having a predominant role at high-frequencies where the VG acts as a non-compact aeroacoustic source.
{"title":"Experimental Characterization of Vortex Generators Induced Noise of Wind Turbines","authors":"D. Kolkman, L. D. Santana, A. V. Garrel, C. Venner, Arlos Arce León, M. Sanders","doi":"10.2514/6.2018-2800","DOIUrl":"https://doi.org/10.2514/6.2018-2800","url":null,"abstract":"The wind energy industry is progressively aiming towards larger wind turbine size as a means of increasing energy production efficiency. Wind turbine rotor blades are becoming significantly more flexible and have an increased risk of structural failure. Thicker airfoil profiles can be used to increase the structural strength. However, thicker airfoils are more prone to flow separation with adverse effect on power generation. Vortex generators (VGs) are an effective solution to delay flow separation. However, VGs significantly increase radiated noise levels. This presented research experimentally investigates the effect of VGs on blade noise production. Specifically, the influence of the VG geometric shape is evaluated while keeping the dimensions constant. Wind tunnel tests have been carried out on a NACA 0018 that is equipped with triangular vane-type VGs specifically designed for the test conditions. A microphone phased array is used to assess the radiated noise using the beamforming technique. The results show that the VGs significantly contribute to increase the blade noise production with having a predominant role at high-frequencies where the VG acts as a non-compact aeroacoustic source.","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114615414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Geyer, D. Moreau, J. Giesler, Philipp M Hall, E. Sarradj, C. Doolan
The flow around a wall-mounted finite airfoil with natural transition can lead to complex tonal characteristics in the corresponding aeroacoustic noise spectra. While many of the flow features and noise generating mechanisms are well understood, there are still open questions, for example regarding the influence of the airfoil shape. In the present paper, the influence of the thickness of a wall-mounted finite airfoil on the noise generation is examined experimentally. To this end, detailed measurements were performed on a NACA0012 airfoil and a NACA0018 airfoil in an open jet aeroacoustic wind tunnel at various flow speeds and angles of attack. This includes acoustic measurements with a planar microphone array as well as measurements of the surface pressure fluctuations using flush-mounted pressure capsules. In addition, surface flow visualization experiments were conducted on the NACA0012 airfoil. The results show that the thickness of the airfoil has a notable influence on the tonal noise generation, which is visible both in the sound pressure level spectra as well as in the wall pressure spectra. At small geometric angles of attack and high flow speeds, the thinner NACA0012 generates a strong tone with weaker side tones, whereas the NACA0018 generates a set of equispaced tones. At higher angles the NACA0012 does not radiate tonal noise, while the NACA0018 now generates this strong tone with weaker side tones.
{"title":"Measurement of the noise generated by wall-mounted airfoils of different thickness","authors":"T. Geyer, D. Moreau, J. Giesler, Philipp M Hall, E. Sarradj, C. Doolan","doi":"10.2514/6.2018-3796","DOIUrl":"https://doi.org/10.2514/6.2018-3796","url":null,"abstract":"The flow around a wall-mounted finite airfoil with natural transition can lead to complex tonal characteristics in the corresponding aeroacoustic noise spectra. While many of the flow features and noise generating mechanisms are well understood, there are still open questions, for example regarding the influence of the airfoil shape. In the present paper, the influence of the thickness of a wall-mounted finite airfoil on the noise generation is examined experimentally. To this end, detailed measurements were performed on a NACA0012 airfoil and a NACA0018 airfoil in an open jet aeroacoustic wind tunnel at various flow speeds and angles of attack. This includes acoustic measurements with a planar microphone array as well as measurements of the surface pressure fluctuations using flush-mounted pressure capsules. In addition, surface flow visualization experiments were conducted on the NACA0012 airfoil. The results show that the thickness of the airfoil has a notable influence on the tonal noise generation, which is visible both in the sound pressure level spectra as well as in the wall pressure spectra. At small geometric angles of attack and high flow speeds, the thinner NACA0012 generates a strong tone with weaker side tones, whereas the NACA0018 generates a set of equispaced tones. At higher angles the NACA0012 does not radiate tonal noise, while the NACA0018 now generates this strong tone with weaker side tones.","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117269217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tonal Noise Transmission through a Non-Axisymmetric Turbine OGV with Separated Flow: Prediction and Measurements","authors":"J. R. Aparicio, A. Serrano","doi":"10.2514/6.2018-3914","DOIUrl":"https://doi.org/10.2514/6.2018-3914","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115804198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental and Numerical Study of Passive Gap Noise","authors":"L. Erbig, Nan Hu, S. Lardeau","doi":"10.2514/6.2018-3595","DOIUrl":"https://doi.org/10.2514/6.2018-3595","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125382413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A weakly compressible, wall-modelled Large-Eddy Simulation (WMLES) solver is used to predict the aerodynamic flow and far-field acoustics of the 4-wheel Rudimentary Landing Gear (RLG) from the Benchmark Problems for Airframe Noise Computations (BANC). The main purposes of this study are to test (1) methods to computationally model the mounting plane that was used in the experiments and (2) choice of solid FW-H surfaces to correctly predict the far-field noise including the installation effects. Both weakly compressible and incompressible solvers were used to simulate the flowfield. The reflective mounting plane was modelled with slip and no-slip boundary conditions. Predictions of far-field acoustics using different solid FW-H surfaces are compared with experimental measurements. With an incompressible solver, reflection peaks were absent from the predictions using only the landing gear as an integral surface, but could be partially recovered by adding the landing gear’s mirrored image into the FW-H integral surface. For the weakly compressible solutions, these reflection peaks were captured by using the landing gear surface as the FWH integral surface. However, the peaks were amplified by including the landing gear’s mirrored image. Using an FW-H integral surface that consisted of the landing gear and slip-wall mounting plane was found to generate excessive low-frequency far-field noise with a weakly compressible solver. The over-prediction with these FW-H surfaces, was eliminated by modelling the mounting plane with the exact dimensions and a no-slip boundary conditions.
{"title":"A Numerical Study of Installation Effects of the Rudimentary Landing Gear Benchmark Problem","authors":"Yun-ge Hou, D. Angland, A. Scotto","doi":"10.2514/6.2018-3468","DOIUrl":"https://doi.org/10.2514/6.2018-3468","url":null,"abstract":"A weakly compressible, wall-modelled Large-Eddy Simulation (WMLES) solver is used to predict the aerodynamic flow and far-field acoustics of the 4-wheel Rudimentary Landing Gear (RLG) from the Benchmark Problems for Airframe Noise Computations (BANC). The main purposes of this study are to test (1) methods to computationally model the mounting plane that was used in the experiments and (2) choice of solid FW-H surfaces to correctly predict the far-field noise including the installation effects. Both weakly compressible and incompressible solvers were used to simulate the flowfield. The reflective mounting plane was modelled with slip and no-slip boundary conditions. Predictions of far-field acoustics using different solid FW-H surfaces are compared with experimental measurements. With an incompressible solver, reflection peaks were absent from the predictions using only the landing gear as an integral surface, but could be partially recovered by adding the landing gear’s mirrored image into the FW-H integral surface. For the weakly compressible solutions, these reflection peaks were captured by using the landing gear surface as the FWH integral surface. However, the peaks were amplified by including the landing gear’s mirrored image. Using an FW-H integral surface that consisted of the landing gear and slip-wall mounting plane was found to generate excessive low-frequency far-field noise with a weakly compressible solver. The over-prediction with these FW-H surfaces, was eliminated by modelling the mounting plane with the exact dimensions and a no-slip boundary conditions.","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129793576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Community noise assessment for aircrafts with contra-rotating open rotor power plants","authors":"L. Sanders","doi":"10.2514/6.2018-2819","DOIUrl":"https://doi.org/10.2514/6.2018-2819","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130228899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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