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研究生:鄭博毅
研究生(外文):Cheng, Po-Yi
論文名稱:線陣列超音波換能器於質子交換膜燃料電池石墨雙極板的聲場
論文名稱(外文):Acoustic Field Induced by Linear Array Ultrasonic Transducers in Graphite Bipolar Plates for PEM Fuel Cells
指導教授:尹慶中
指導教授(外文):Yin, Ching-Chung
學位類別:碩士
校院名稱:國立交通大學
系所名稱:機械工程學系
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2010
畢業學年度:98
語文別:中文
論文頁數:101
中文關鍵詞:質子交換膜燃料電池聲場指向性暫態分析線陣列超音波探頭
外文關鍵詞:PEM fuel cellacoustic directivitytransient analysislinear array ultrasonic transducer
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質子交換膜燃料電池反應生成水的管理是相關產品研發的一項重要課題,本研究應用數值方法分析陣列超音波穿透石墨流道雙極板,模擬超音波可視化監測反應生成水。石墨流道雙極板特性經接觸式超音波方法量測,確認應為石墨複材,材料特性接近等向性材料。並以相同之實驗架構獲得石墨流道板不同區域與狀態之超音波反射訊號,當流道內有水存在時,超音波回波訊號具明顯之差異。使用聚焦式沒水超音波探頭對石墨複材流道板進行線掃描,結果顯示聚焦探頭能清楚辨別不同流道內水的分佈。
為設計合適的陣列探頭,探討單晶壓電換能器在半無限域固體基材中激發的聲場指向性,作為設計陣列超音波換能器的依據。以有限元素法分別對於介質為等向性固體之石墨複材及異向性純石墨進行聲場指向性的模擬分析。純石墨材料的軸向與橫向剛性差異太大,單晶壓電探頭激發的聲場主瓣較窄,聲波相位干涉產生的側瓣不明顯,聲束的擴散角小,石墨複材則相反。根據分析結果設計陣列超音波換能器,再利用暫態分析模擬設計之效果,確認可辨識不同區域水的分佈。

Water management is an important issue to improve performance of proton-exchange-membrane (PEM) fuel cells. In order to understand the feasibility of monitoring water production in PEM fuel cells using ultrasonic visualization, this thesis numerically studies linear array induced ultrasound propagation in graphite bipolar plates with machined flow channels. The material properties of graphite bipolar flow channels were experimentally characterized. Experimental results indicate that it is nearly an isotropic material. Comparing the ultrasonic signals acquired in different states and areas of graphite bipolar plates, the reflected echoes have significant changes when water appears in flow channels. According to the B-scan signals of graphite bipolar plates using immersion focusing ultrasonic transducer, the distribution of water can be clearly determined.
Based on the investigation of the acoustic field induced by single element piezoelectric transducer attached on surface of semi-infinite solids, a linear array ultrasonic transducer was further designed. Both graphite composite and pure graphite are considered as acoustic media under investigation. Single element generated ultrasound in pure graphite has narrow main lobe due to its hexagonal anisotropy. The side lobe produced by acoustic phase interference is relatively small. It results that acoustic directivity of sound beam has smaller divergence angle in pure graphite than graphite composite. Transient analysis for acoustic field induced by linear array ultrasonic transducer in graphite bipolar plate indicates that the water distribution in the flow channels can be successfully discriminated.

中文摘要 i
英文摘要 ii
誌謝 iv
目錄 v
表目錄 viii
圖目錄 ix
第一章 緒論 1
1.1研究背景 1
1.2文獻回顧 3
1.2.1質子交換膜燃料電池生成水的管理研究 3
1.2.2固體介質之聲場分佈研究 3
1.2.3合成孔徑成像法 4
1.3研究目的 5
1.4內容簡介 5
第二章 理論說明 6
2.1壓電材料特性方程式 6
2.2有限元素分析 7
2.2.1時諧分析(Harmonic Analysis) 7
2.2.2暫態分析(Transient Analysis) 9
2.2.3 阻尼設定 10
2.3 彈性波平均功率表示式 11
2.4 合成孔徑成像原理 13
2.4.1延遲加成法 13
2.4.2角頻譜法 14第三章 實驗量測與結果討論 17
3.1石墨複材流道板之超音波反射訊號實驗 17
3.1.1實驗方法及其流程 17
3.1.2非流道區反射訊號實驗 18
3.1.3流道區反射訊號實驗 19
3.1.4石墨流道板材料常數的量測 20
3.1.5 小結 22
3.2石墨複材流道板超音波線掃瞄實驗 23
3.2.1實驗架構 23
3.2.2實驗原理與說明 24
3.2.3探頭特性量測 26
3.2.4流道區之時域訊號分析 26
3.2.5超音波線掃描影像 27
3.2.6 小結 28
第四章 數值模擬分析與討論 29
4.1單晶壓電換能器的聲場分析 29
4.1.1壓電元素厚度計算 30
4.1.2 單晶壓電換能器在固體中的聲場分析 31
4.1.3 單晶壓電換能器在固體中的聲場分析結果 32
4.1.4 小結 33
4.2陣列式超音波探頭設計 33
4.2.1設計參數定義 33
4.2.2 設計準則 34
4.2.3 設計結果 35
4.3 石墨流道板之超音波反射訊號模擬分析 36
4.3.1 有限元素暫態波傳分析之模擬條件 36
4.3.1.1 分析元素選擇與材料係數 36
4.3.1.2 模擬激發壓電陶瓷的方式與設定 37
4.3.2 石墨流道板之暫態模擬 38
4.3.2.1 石墨流道板暫態波傳模擬 39
4.3.2.2 非流道區超音波回波訊號模擬 39
4.3.2.2.1 邊界條件的設定 40
4.3.2.2.2 基底材料的影響 40
4.3.2.3 非流道區石墨流道板超音波反射訊號模擬41
4.3.2.4 流道區超音波回波訊號模擬 42
4.3.4.5 流道區陣列式超音波探頭回波訊號模擬 43
4.3.3 小結 45
第五章 結論與展望 46
5.1結論 46
5.1.1 實驗量測結果分析 46
5.1.2 數值分析結果 47
5.1.2.1 指向性分析 47
5.1.2.2 陣列式超音波探頭設計 47
5.1.2.3 石墨流道板之超音波反射訊號模擬分析 47
5.2未來展望 48
參考文獻 49
附錄一 51
附表 54
附圖 58
[1] D. Singh, D.M. Lu and N. Djilali, 1999, “A two-dimensional analysis of mass transport in proton exchange membrane fuel cells”, International Journal of Engineering Science, 37, 431-452.
[2] G.J.M. Janssen, M.L.J. Overvelde, “Water transport in the proton-exchange membrane fuel cell:measurements of the effective drag coefficient”, Journal of Power Sources, 101, 117-125.
[3] K. Tüber, D. Pócza and C. Hebling, 2003, “Visualization of water buildup in the cathode of a transparent PEM fuel cell,” Journal of Power Sources, 124(2), 403-414.
[4] O. Lottin, B. Antoine, T. Colinart, S. Didierjean, G. Maranzana, C. Moyne and J. Ramousse, 2009, “Modelling of the operation of polymer exchange membrane fuel cells in the presence of electrodes flooding,” International Journal of Thermal Sciences, 48(1), 133-145.
[5] H. Lamb, 1904, “On the propagateion of tremors over the surface of an elastic solid,” Phil. Trans. R. Soc., A203, 1-42.
[6] G. F. Miller and H. Pursey, 1954, “The field and radiateon impedance of mechanical radiators on the free surface of a semi-infinite isotropic solid,” Proc. R. Soc., A223, 521-541.
[7] L. Cagniard, 1935, Reflexion et Refraction des Ondes Seismiques Progressives, Gauthiers-Villars, Paris.
[8] A. T. De Hoop, 1958, Representation Theorems for the Displacement in an Elastic Solid and Their Application to Elastodynamic Diffraction Theory, Thesis, Technische Hogeschool Te Delft.
[9] K. Wu, P. B. Nagy, and L. Adler, 1991, “Far-field radiation of a vibrating point source in anisotropic media,” Journal of Nondestructive Evaluation, 10(2), 71-78.
[10] J.J. Flaherty, K.R. Erikson, V.M. Lund. Synthetic aperture ultrasound imaging systems, United States Patent, US 3,548,642, 1967.
[11] G.P. Singh and J.W. Davis, “Multiple transducer ultrasonic techniques,” ASNT, Nondestructive Testing Handbook, Vol. 7,P. Mcintire ed. Ultrasonic Testing, 2nd edition, 267-309, 1991.
[12] S.F. Burch and J.T. Burton, “Ultrasonic synthetic aperture focusing using planar pulse-echo transducer, ” Ultrasonic, 275-281, 1984.
[13] J.W. Goodman, Introduction to Fourier Optics, Chap. 3, 2nd Edition, McGraw-Hill, New York, 1996.
[14] L.J. Busse, “Three-dimentional imaging using a frequency-domain synthetic aperture focusing technique,” IEEE Transaction of Ultrasonics, Ferroelectrics, and Frequency Control, 39(2), 174-179, 1992
[15] K.-J. Bathe and E.L. Wilson, Numerical Methods in Finite Element Analysis, Chap.8, PP.308-344, Prentice-Hall, Englewood Cliffs, New Jersey, 1976.
[16] O.E. Mattiat, Ultrasonic Transducer Materials, PP.76, Plenum, New York, 1971.

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