Multipole expansion approach for rotor noise prediction

IF 4.3 2区 工程技术 Q1 ACOUSTICS
Felice Fruncillo , Paolo Luchini , Flavio Giannetti
{"title":"Multipole expansion approach for rotor noise prediction","authors":"Felice Fruncillo ,&nbsp;Paolo Luchini ,&nbsp;Flavio Giannetti","doi":"10.1016/j.jsv.2025.119317","DOIUrl":null,"url":null,"abstract":"<div><div>This paper presents a frequency-domain model of rotor tonal noise, based on a multipole expansion of the radiated field. The expressions for loading and thickness noise are derived in hovering condition, employing the results of compressible thin airfoil theory. The multipole coefficients are obtained as integrals of the boundary conditions in the plane of rotation, by considering the symmetry properties of the Green’s function. The terms of the expansion are independent of the observer point. As a result, once calculated, they allow for the solution to be obtained at any desired point in the field. This characteristic is not present in the main theories developed in the literature, and it allows for computational advantages. It is shown how the derived expressions can be traced back to Hanson’s helicoidal surface theory, which is used to validate the implementation. It results that even a single term in the expansion is capable of yielding accurate results in the far field. Conversely, the near field requires several coefficients of the series to achieve convergence, unless the low-frequency assumption is met. The chordwise compactness hypothesis is examined and a simplified model for preliminary calculations is proposed.</div></div>","PeriodicalId":17233,"journal":{"name":"Journal of Sound and Vibration","volume":"617 ","pages":"Article 119317"},"PeriodicalIF":4.3000,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Sound and Vibration","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022460X25003918","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ACOUSTICS","Score":null,"Total":0}
引用次数: 0

Abstract

This paper presents a frequency-domain model of rotor tonal noise, based on a multipole expansion of the radiated field. The expressions for loading and thickness noise are derived in hovering condition, employing the results of compressible thin airfoil theory. The multipole coefficients are obtained as integrals of the boundary conditions in the plane of rotation, by considering the symmetry properties of the Green’s function. The terms of the expansion are independent of the observer point. As a result, once calculated, they allow for the solution to be obtained at any desired point in the field. This characteristic is not present in the main theories developed in the literature, and it allows for computational advantages. It is shown how the derived expressions can be traced back to Hanson’s helicoidal surface theory, which is used to validate the implementation. It results that even a single term in the expansion is capable of yielding accurate results in the far field. Conversely, the near field requires several coefficients of the series to achieve convergence, unless the low-frequency assumption is met. The chordwise compactness hypothesis is examined and a simplified model for preliminary calculations is proposed.
转子噪声预测的多极展开法
提出了一种基于辐射场多极展开的转子噪声频域模型。利用可压缩薄翼型理论推导了悬停状态下载荷和厚度噪声的表达式。考虑格林函数的对称性,以旋转平面上边界条件的积分形式得到多极系数。展开的项与观测点无关。因此,一旦计算出来,它们就允许在现场的任何期望点上获得解。在文献中发展的主要理论中不存在这种特征,并且它允许计算优势。它显示了如何推导表达式可以追溯到汉森的螺旋曲面理论,这是用来验证实现。结果表明,即使在展开式中的单个项也能够在远场中产生准确的结果。相反,除非满足低频假设,否则近场需要级数的多个系数才能收敛。对弦向紧性假设进行了检验,并提出了初步计算的简化模型。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Journal of Sound and Vibration
Journal of Sound and Vibration 工程技术-工程:机械
CiteScore
9.10
自引率
10.60%
发文量
551
审稿时长
69 days
期刊介绍: The Journal of Sound and Vibration (JSV) is an independent journal devoted to the prompt publication of original papers, both theoretical and experimental, that provide new information on any aspect of sound or vibration. There is an emphasis on fundamental work that has potential for practical application. JSV was founded and operates on the premise that the subject of sound and vibration requires a journal that publishes papers of a high technical standard across the various subdisciplines, thus facilitating awareness of techniques and discoveries in one area that may be applicable in others.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信