臺灣博碩士論文加值系統

本文主要分析迴轉式壓縮機之消音罩的消音特性，其數值模型利用聲學模組ANSYS Acoustic ACTx R15.0進行聲場分析。其目的在建立一套有限元素分析方式應用於壓縮機消音罩之研發，並提供消音罩改善設計的方向，使設計者在事前可對消音罩進行消音分析與研究。
文中主要分為兩個部分，第一部分為波導管連接消音罩模型，假設出口為開放性邊界條件之設定並將實際實驗量測之模型匯入ANSYS聲學模組進行分析，比較實驗結果時以空氣為聲音傳導介質且以傳遞損失作為主要消音性能評估之指標，實驗結果與數值模擬結果趨勢相同。第二部分為消音罩設計，為探討消音罩本身之內部聲場，將出入口波導管皆移除，模擬時以R22a冷媒為聲音傳導介質且以噪音衰減作為主要消音性能評估之指標。

This research focused on the noise reduction characteristics of the muffler in a rotary compressor. A finite element software, ANSYS Acoustic ACTx R15.0, was used to obtain the mathematical solutions. This research was split up into two sections. At the beginning, the muffler was connected to waveguides with anechoic outputs in the simulation model. The introduction of waveguides is to guarantee the existence of plane sound wave in the calculation of Transmission Loss (TL). The acoustic medium is air. Then, an experiment was performed. The numerical results and experimental results compare well if the output boundary of waveguides was chosen the open boundary. The second part of the research is the study of a real muffler without waveguides. The acoustic medium R22a. Another index, Noise Reduction (NR), was adopted to assess the noise reduction performance. A parameter study of various geometric parameters was reported. Design suggestions of the muffle were also given.

目錄
摘要 I
Abstract II
致謝 III
目錄 IV
圖目錄 VIII
表目錄 XII
符號說明 XIII
第一章 緒論 1
1-1 前言 1
1-2 文獻回顧 2
1-3 論文架構 5
第二章 基本理論 6
2-1 聲學基本理論 6
2-1-1 波動方程式 6
2-1-2 平面波 9
2-1-3 管路聲學阻抗 11
2-2 消音器功能與類型 11
2-2-1 反應型消音器 12
2-2-2 消散型消音器 12
2-3 消音性能評估指標 12
2-3-1 傳遞損失 13
2-3-2 噪音衰減 13
2-3-3 插入損失 14
第三章 數值模型 16
3-1 數值模擬軟體簡介 16
3-2 研究方法與流程 17
3-3波導管連接消音罩模型 18
3-3-1傳遞損失計算方式 18
3-3-2波導管尺寸設計與分析 20
3-3-3波導管連接消音罩有限元素模型 21
3-4波導管連接消音罩聲場模擬設定 22
3-4-1加入空氣阻力因素 22
3-4-2聲固耦合分析 23
3-4-3簡諧分析 23
3-4-4暫態分析 24
第四章 實驗規劃 25
4-1實驗設計 25
4-2實驗設備 26
4-3實驗量測 26
4-4訊號處理與傳遞損失運算 27
第五章 波導管連接消音罩之聲場模擬結果與討論 28
5-1 波導管形狀選擇 28
5-2 其他可能影響聲場之因素 29
5-2-1 空氣黏滯係數 29
5-2-2 聲固耦合 29
5-3 波導管連接消音罩之聲場分析 30
5-3-1 不同輸入源之比較 31
5-3-2 簡諧分析與暫態分析之比較 31
5-3-3 無迴響邊界與開放性邊界之比較 31
5-3-4 數值模擬結果與實驗結果比較 32
第六章 開放性邊界之聲場模擬結果與討論 33
6-1聲場介質之比較 33
6-2單一管徑波導管之影響 34
6-3改變消音罩幾何尺寸 36
6-3-1改變消音罩高度 36
6-3-2改變消音罩出口位置 37
6-3-3改變消音罩出口形狀 39
6-3-4改變消音罩出口大小 40
6-4以出入口聲壓值探討消音罩之消音特性 41
6-5新設計 42
第七章 結論與未來展望 43
7-1 結論 43
7-2 未來展望 45
參考文獻 46

甲公司迴轉式壓縮機噪音量測資料

白明憲，2006，工程聲學，全華圖書股份有限公司，台北市。

林家煌，2015，壓縮機消音罩聲場模擬分析與實驗，國立中央大學機械工程研究所碩士論文，桃園市。

季振林，2015，消聲器聲學理論與設計，科學出版社，北京市。

虎門科技，2016，ANSYS Workbench MAPDL (Using Command Objects)，虎門科技有限公司，台北市。

張濤，2013，ANSYS APDL 參數化有限元分析技術及其應用實例，中國水利水電出版社，北京市。

戴禮擎，2004，消音器性能評估方法之解析，國立台灣科技大學碩士論文，台北市。

ANSYS, 2014, ANSYS Acoustic R15.0 Training Lecture Notes, ANSYS, Inc.

ANSYS, 2014, ANSYS Mechanical APDL Acoustic Analysis Guide, ANSYS, Inc.
ASTM E1050-12, 2014, “Standard Test Method for Impedance and Absorption of Acoustical Materials Using a Tube, Two Microphones and a Digital Frequency Analysis System”.

Atig, M., Dalmont, J-P., and Gilbert, J., 2010, “Termination impedance of open-ended cylindrical tubes at high sound pressure level”, Comptes rendus de l’Académie des sciences. Série IIb, Mécanique, Elsevier, 2004, 332 (4), pp.299-304

Bilawchuk, S., and Fyfe, K. R., 2003, “Comparison and Implementation of the Various Numerical Methods Used for Calculating Transmission Loss in Silencer Systems”, Applied Acoustic, Vol. 64, pp. 903-916.

Jhon P., 2008, “Acoustic Waveguides”, University of Colorado, Boulder.

Lee, J. W., 2015, “Optimal topology of reactive muffler achieving target transmission loss values: Design and experiment”, Applied Acoustics, Vol. 88, pp. 104–113.

Mehdizadeh, O. Z. and Paraschivoiu, M., 2005, “A Three-Dimensional Finite Element Approach for Predicting the Transmission Loss in Mufflers and Silencers with No Mean Flow”, Applied Acoustic, Vol. 66, pp. 902-918.

Munjal, M. L., 2014, Acoustics of Ducts and Mufflers, Wiley, New York, U.S.A.

Park, S., Kim, H., Lee, C., Youn, H. and Cho, S., 1994, “The Design of Compressor Muffler”, International Compressor Engineering Conference, pp. 247-252.

Prasad, M. G. and Crocker, M. J., 1983, “Studies of Acoustical Performance of a Multi-Cylinder Engine Exhaust Muffler System”, Journal of Sound and Vibration, Vol. 90, pp. 491-508.

Selament, A. and Ji, Z. L., 1999, “Acoustic Attenuation Performance of Circular Expansion Chambers with extended inlet & outlet”, Journal of Sound and Vibration, Vol. 223, pp. 197-212.

Selament, A. and Ji, Z. L., 2000, “Acoustic Attenuation Performance of Circular Expansion Chambers with Single-Inlet and Double-Outlet”, Journal of Sound and Vibration, Vol. 229, pp. 3-19.

Selameta, A., Deniab, F. D., and Besa, A. J., 2003, “Acoustic behavior of circular dual-chamber mufflers”, Journal of Sound and Vibration, Vol. 265, pp. 967–985.

Seybert, A. F. and Ross, D. F., 1997, “Experimental Determination of Acoustic Properties Using a Two-Microphone Random Excitation Technique”, Journal of the Acoustical Society of America, Vol. 61, pp. 1362-1370.

Tao, Z. and Seybert, A. F., 2003, “A Review of Current Techniques for Measuring Muffler Transmission Loss”, SAE Technical Paper 2003-01-1653.

Wu, C. J., Wang, X. J., and Tang, H. B., 2008, “Transmission loss prediction on a single-inlet double-outlet cylindrical expansion-chamber muffler by using the modal meshing approach”, Applied Acoustic, Vol. 69, pp. 173-178.