氣體流經槽孔型消音器產生之氣動力噪音分析

Aeroacoustics Analysis of Air Flow Passing by Perforated Mulfflers

陳信成(Chen-Shin Cheng)

指導教授 ： 王昭男

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.01868

摘要

本研究主要探討的是氣體流經過槽孔型消音器時，槽孔相關的幾何參數對氣動噪音的影響。藉由建立三維槽孔型消音器之模型並對其劃分網格，再引入有限體積法去做數值運算可得流場分佈，利用所得之紊流資訊進而求得氣動力噪音。為了簡化運算量，對Navier¬-Stokes方程式採用雷諾平均法(RANS)配合 紊流模式求解紊流流場。聲場分析是以Lighthill聲學類比理論之寬頻帶噪音模式(Broadband Noise Source Model，BNS)為基礎，使用Proudman與Curle方程式去計算氣流產生之噪音總量。為確認紊流流場計算及噪音分析的正確性，以模擬之內部聲音能量變化比對實驗量測消音器出口之聲壓值變化，以驗證實驗之可靠度。文中探討的消音器有直通型消音器、雙向延伸管塞型消音器與單向延伸管塞型消音器，並分析不同的槽孔相關幾何參數及不同的流速下，氣流噪音對於消音器的影響，以作為槽孔消音器設計改良的參考依據。

關鍵字

槽孔型消音器 ； 氣動噪音

並列摘要

The purpose of research is to investigate parameters on the impact of aerodynamic noise when perforated muffler is passing by air. By building model of perforated model, dividing muffler into grids and using finite volume method, the low field of the perforated muffler can be solved and aerodynamic noise can be obtain by turbulent data. For simplifying calculation, the Reynolds Averaged Navier-Stokes equation combine with turbulent model are used to solve the turbulent flow. The sound field analysis is based on the Broadband Noise Source (BNS) model. Proundman’s and Curle’s formula are used to evaluate acoustic power per unit volume and surface acoustic power. In order to verify the correctness of the turbulent flow field and noise’s analysis, the study compare internal sound power changes of simulation and external sound pressure changes of experiment. The research have several types of mufflers, straight-through mufflers, one-way extension tube of plug mufflers and two-way extension tube of plug mufflers. At different flow rates and parameters, the impact of aerodynamic noise on perforated muffler can be used as a basis for improved perforated muffler.

並列關鍵字

perforated muffler ； aerodynamic noise

參考文獻

[17] 蔡依妏, ”單腔消音器之流場與氣動力噪音分析”,國立台灣大學工程科學及海洋工程學系碩士論文,2010年6月.

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