International Journal of Aeroacoustics最新文献_第3页

Supersonic jet noise and screech tone suppression using cross-wire 利用交叉线抑制超音速喷气噪声和尖啸声

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-12-29 DOI: 10.1177/1475472x231225628

Kaleeswaran Periyasamy, Kadiresh Parthasarathy Natarajan

{"title":"Supersonic jet noise and screech tone suppression using cross-wire","authors":"Kaleeswaran Periyasamy, Kadiresh Parthasarathy Natarajan","doi":"10.1177/1475472x231225628","DOIUrl":"https://doi.org/10.1177/1475472x231225628","url":null,"abstract":"This experimental investigation is aimed at assessing how the introduction of a cross-wire at the exit of a CD nozzle influences the performance of a supersonic nozzle. The study focuses on cold air jets generated by De Laval nozzles equipped with cross-wires and baseline configurations, particularly at design Mach numbers of 1.5 and 1.75. The investigation involves collecting measurements from the noise field emitted by the cross-wire nozzle with a 2% obstruction at the exit. This passive control approach effectively reduces the occurrence of screech tones in both over-expanded and under-expanded conditions in the azimuthal plane at appropriate operating pressures. Various acoustic parameters, including sound pressure levels (SPL), Strouhal numbers, and the overall sound pressure level spectra (OASPL) are recorded. Schlieren imaging captures images of shock cell patterns, illustrating the impact of shock-associated noise. In comparison to a baseline nozzle, the results demonstrate that a CD nozzle equipped with a cross-wire proves to be a proficient screech tone suppressor, leading to an average reduction of up to 5 dB in OASPL in under-expanded and over-expanded scenarios.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139147260","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

Guest editor biography 特邀编辑简历

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-11-01 DOI: 10.1177/1475472X231219326

引用次数: 0

Guest editor biography 特邀编辑简历

IF 1 4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-11-01 DOI: 10.1177/1475472x231219327

引用次数: 0

Trailing edge serrations for noise control in axial-flow automotive cooling fans 轴流汽车冷却风扇噪声控制的后缘锯齿

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-10-14 DOI: 10.1177/1475472x231206498

Kwang Ho Hur, Basharat Ali Haider, Chang Hyun Sohn

{"title":"Trailing edge serrations for noise control in axial-flow automotive cooling fans","authors":"Kwang Ho Hur, Basharat Ali Haider, Chang Hyun Sohn","doi":"10.1177/1475472x231206498","DOIUrl":"https://doi.org/10.1177/1475472x231206498","url":null,"abstract":"This study investigated the use of trailing edge serrations to reduce the noise generated by axial-flow automotive cooling fans. Three different serration profiles (sinusoidal, rectangular, and triangular) were examined, with the profiles being extended radially along the entire blade length and truncated at half the blade length while keeping the dimensionless wave number k ∗ and wave amplitude 2 h ∗ constant. The simulations employed a hybrid URANS-LES solver for the flow field and Ffowcs Williams-Hawkings analogy for the sound field, corresponding to the maximum volumetric flow rate and fan rotational speed. Acoustic pressure measurements were taken at multiple receivers upstream and downstream of the fan, and the overall sound pressure level was computed based on the results. Furthermore, the study also compared the aerodynamic performance of all serration types with the baseline fan, revealing that the baseline fan was relatively more efficient than their serrated counterparts. Despite the reduced efficiency, the trailing edge serrations offered significant noise reduction benefits of up to 10 dB, making them a promising solution for improving acoustic comfort in automotive cooling systems.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135800519","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

Acoustic characteristics of jets impinging on permeable plates 射流冲击透水板的声学特性

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-10-10 DOI: 10.1177/1475472x231206496

Abhijit Dhamanekar, K Srinivasan

{"title":"Acoustic characteristics of jets impinging on permeable plates","authors":"Abhijit Dhamanekar, K Srinivasan","doi":"10.1177/1475472x231206496","DOIUrl":"https://doi.org/10.1177/1475472x231206496","url":null,"abstract":"This article explores the acoustic characteristics and the relevant flow features of jets impinging on permeable plates. Noise generated due to the interaction of the jet with permeable plates is compared with jets impinging on an impermeable plate and the corresponding free jet. This study systematically measures various parameters, including pore size, porosity, and pressure drop, to precisely quantify the permeability of the plates using the Forchheimer equation. The focus is on investigating the impact of permeability on noise reduction. An acoustic study is performed by carrying out blow-up and blow-down tests to find the effect of permeability at different nozzle pressure ratios and different nozzle-plate spacings. An extensive directivity study is conducted to find the directionality of acoustic emissions and calculate acoustic power. It is found that the overall sound pressure level is lower for the jets impinging on the permeable plates compared to the impermeable plates in subsonic cases. It is also observed that the insertion of the permeable plates in supersonic jets generates less noise compared to the corresponding free jet. It is found that most of the tones are absent in the case of permeable plates for supersonic jets, whereas the tones are present with lesser amplitude compared to jets impinging on impermeable plates for subsonic and transonic jets. Finally, flow measurement and flow visualization studies are carried out to understand the flow physics responsible for the noise variance. This study illuminates that the passage of flow through the porous plate results in the reduction of wall-jet velocities, thereby suppressing the turbulent mixing noise. The absence of shock oscillations in front of the permeable plate is identified as the cause of the mitigation of impinging tones.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136358363","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

Influence of nozzle external geometry on the emission of screech tones 喷嘴外部几何形状对尖叫音调发射的影响

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-10-05 DOI: 10.1177/1475472x231199185

David Morata, Dimitri Papamoschou

{"title":"Influence of nozzle external geometry on the emission of screech tones","authors":"David Morata, Dimitri Papamoschou","doi":"10.1177/1475472x231199185","DOIUrl":"https://doi.org/10.1177/1475472x231199185","url":null,"abstract":"The effect of external nozzle geometry on the emission of screech tones was studied experimentally. Four conical reflector surfaces, with half-angles ranging from 60° to 90°, were installed around the exit of a round convergent nozzle. The investigation focused on two closely spaced fully-expanded Mach numbers, M j = 1.32 and 1.34. The acoustic far-field was surveyed by a microphone phased array that included a continuously-scanning microphone, the latter enabling high spatial resolution. The isolated jets contained well-known screech mode B and its harmonics. Addition of the reflectors caused significant changes in the modal emission pattern, with tones traditionally linked to mode C occurring at M j = 1.34 but not at M j = 1.32. Tonal components associated with new modes E and F emerge at both Mach numbers when the cone half-angle is 60° or 70°. The noise source distribution generally elongates with decreasing cone angle. Some modes show clear scattering from the reflectors, while others do not. The study underscores the complexity that initial conditions can impart on the modal structure of screech and demonstrates the capability of the continuous-scan beamforming technique in resolving fine features of the source.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135480822","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

Analysis of vortex structures evolution and aeroacoustic characteristics in the ultra-high-speed elevator ring-gap flow field 超高速电梯环隙流场涡结构演化及气动声学特性分析

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-10-05 DOI: 10.1177/1475472x231206892

Qing Zhang, Chaoyue Li, Ruijun Zhang, Yulei Wang

{"title":"Analysis of vortex structures evolution and aeroacoustic characteristics in the ultra-high-speed elevator ring-gap flow field","authors":"Qing Zhang, Chaoyue Li, Ruijun Zhang, Yulei Wang","doi":"10.1177/1475472x231206892","DOIUrl":"https://doi.org/10.1177/1475472x231206892","url":null,"abstract":"The continuous improvement of elevator speed has made the issue of aerodynamic noise in the hoistway more prominent. Previous research has usually focused on the characteristics of aerodynamic loads and related safety issues, and little attention has been paid to the problem of flow-induced noise. This paper established a three-dimensional geometric configuration of the ultra-high-speed elevator to study the flow behavior and aerodynamic acoustic characteristics in the hoistway using well-validated large eddy simulations. Firstly, we analyzed the unsteady flow behavior in the ring-gap flow field using large eddy simulations and captured the transient vortex structure in the flow field using the Q-criterion. We then predicted the far-field aerodynamic noise of the elevator car using the Lighthill-Curle aerodynamic acoustic equations. The results showed that the factors affecting the sound source intensity of the elevator car include the shedding position and intensity of the vortex structures. By adjusting the shedding position and reducing the intensity of the vortex structure, the sound source intensity of the elevator car wall could be effectively controlled. The change of the blocking ratio could not affect the attenuation of aerodynamic noise in the hoistway, but the increase of the blocking ratio could lead to an increase in the turbulent kinetic energy intensity and peak SPL in the hoistway. Therefore, the blocking ratio should be kept within 0.65 when designing the hoistway structure dimensions.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135481758","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

Machine learning methods for multi-rotor UAV structural damage detection based on MEMS sensor 基于MEMS传感器的多旋翼无人机结构损伤检测机器学习方法

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-10-05 DOI: 10.1177/1475472x231206495

Yumeng Ma, Faizal Mustapha, Mohamad Ridzwan Ishak, Sharafiz Abdul Rahim, Mazli Mustapha

引用次数: 0

Modeling, design, and optimization of a dielectric elastomer acoustic liner 介电弹性体声学衬垫的建模、设计与优化

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-10-03 DOI: 10.1177/1475472x231199187

Chelsea Solano, Louis Cattafesta

{"title":"Modeling, design, and optimization of a dielectric elastomer acoustic liner","authors":"Chelsea Solano, Louis Cattafesta","doi":"10.1177/1475472x231199187","DOIUrl":"https://doi.org/10.1177/1475472x231199187","url":null,"abstract":"The modeling, design, and optimization of an embedded dielectric elastomer (DE) membrane acoustic liner is considered. The acoustic impedance of the liner is modified when the DE is subjected to voltage, resulting in a reduction of the in-plane stress. A lumped element model of an embedded dielectric elastomer acoustic liner is derived and validated in a normal incidence impedance tube and is subsequently used to optimize its performance. The optimization cost functions include (1) maximization of the average absorption coefficient over a targeted frequency range, 400 – 1600 Hz and (2) maximization of the change in the liner fundamental resonance frequency when the membrane is activated. Good agreement between measured and predicted absorption is observed. Tuning of the resonant frequency requires a numerical solution for resonance using the imaginary part of the impedance, since a simple analytical expression for resonance cannot be derived due to the complex coupling between the acoustics of the liner and the electro-mechanics of the DE membrane. Nonetheless, resonant frequency shifts predicted with the lumped element model compare favorably to those measured with the activated liner sample, with a shift of 213 Hz.","PeriodicalId":49304,"journal":{"name":"International Journal of Aeroacoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135695604","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

Phased array microphone measurement of a ducted low-speed axial flow fan at various operating points with the involvement of the acoustically transparent duct technique 采用声透明管道技术，相控阵传声器测量了管道低速轴流风机在不同工况下的性能

4区工程技术

International Journal of Aeroacoustics Pub Date : 2023-09-30 DOI: 10.1177/1475472x231206494

Bálint Lendvai, Tamás Benedek

引用次数: 0