本文以光纖探針為感測器，量測碎波氣泡的體積分率，同時以水中麥克風收集氣泡噪音，使用Gabor轉換分析氣泡大小與數量。本文進行三項實驗，實驗一為使用光纖探針感測含氣泡液體體積分率之率定實驗，在含氣泡液體的圓柱管中進行實驗，使用統計迴歸分析實驗數據以獲得率定曲線；實驗二為使用光纖探針陣列量測碎波氣泡體積分率之實驗，在水利及海洋工程學系雷射實驗室的造波水槽中進行，波浪由造波機製造並且通過矩形模型，模擬波浪通過潛堤而且發生碎波的現象。針對碎波氣泡體積分率的研究，本文以光纖為感測元件，設計陣列式光纖感測探針，分佈在碎波的發生範圍之內，同步量測同一垂直斷面位置、不同深度的氣泡體積分率。實驗三為使用水中麥克風量測氣泡噪音之實驗。設置水中麥克風於碎波流場，量測波浪通過潛堤模型而產生之碎波噪音，計算各種實驗條件下氣泡數量和大小。由於碎波帶侷限於一有限範圍之內，各位置的局部體積分率，隨著碎波帶的範圍與氣泡數量多寡而異，實驗結果顯示，最大的局部體積分率為28 %，發生於實驗條件為堤寬50 公分的碎波之中；氣泡數量以波高條件為4公分的碎波實驗最多，其平均氣泡數量為133.4顆。

Fiber optic probes and hydrophones were used to determine the characteristics of the air bubbles entrained by breaking waves in this text. Three experiments were conducted herein. Firstly, the first experiment establishes the rating curve for fiber optic probe to measure local void fraction of bubbly liquid in the cylinder pipe with regressive analysis. Secondly, fiber-optic-probe array was implemented to measure local void fraction of the air bubbles entrained by breaking waves. This text proposes fiber-optic-probe array distributed in the surf zone to detect the air bubbles entrained in each region of surf zone at the same time, and transforms data into local void fraction. Thirdly, the hydrophone set up near the surf zone was used to receive noise radiated by the air bubbles, and calculating the quantity and size distribution of the air bubbles from received noise with Gabor transform. The results of this text show that the maximum of local void fraction is 28 %, which produced in the case of obstacle width of 50 cm. The maximum of average bubble numbers are 133.4, which occurred in the case of wave height of 4 cm.

1.Andreas, E. L. and E. C. Monahan, “The role of whitecap bubbles in air-sea heat and moisture exchange,” J. Phys. Oceanogr., Vol. 30, pp. 433-442, 2000.
2.Blake, J. R. and D. C. Gibson, “Growth and collapse of a vapor cavity near a free surface,” J. Fluid Mech., Vol.111, pp. 123-144, 1981.
3.Barrau, E., N. Rivière, Ch. Poupot, A. Cartellier, “Single and double optical probes in air-water two-phase flows：real time signal processing and sensor performance,” Int. J. Multiphase Flow, Vol. 25, pp. 229-256, 1999.
4.Commander, K. W. and A. Prosperetti, “Linear pressure waves in bubbly liquids：Comparison between theory and experiments,” J. Acoust. Soc. Am., Vol. 85, pp. 732-746, 1989.
5.Cartellier, A., “Optical probes for local void fraction measurements：Characterization of performance,” Rev. Sci. Instrum., Vol. 61, No. 2, pp. 874-886, 1990.
6.Cartellier, A., “Simultaneous void fraction measurement, bubble velocity, and size estimate using a single optical probe in gas-liquid two-phase flows,” Rev. Sci. Instrum., Vol. 63, No. 11, pp. 5442-5453, 1992.
7.Chang, K. A., Hsu, T. J., Liu, P. L. F., “Vortex generation and evolution in water waves propagating over a submerged rectangular obstacle Part I. Solitary waves,” Coast. Eng., Vol. 44, pp. 13-36, 2001.
8.Chang, K. A., H. J. Lim, C. B. Su, “Fiber optic reflectometer for velocity and fraction ratio measurements in multiphase flows,” Rev. Sci. Instrum., Vol. 74, No. 7, pp. 3559-3565, 2003.
9.Chang, K. A., Hsu, T. J., Liu, P. L. F., “Vortex generation and evolution in water waves propagating over a submerged rectangular obstacle, Part II：Cnoidal waves,” Coast. Eng., Vol. 52, pp. 257-283, 2005.
10.EL-Kamash, M. R. Loewen, N. Rajaratnam, “Measurements of void fraction and bubble properties on a stepped chute using a fiber-optic probe,” Can. J. Civ. Eng., Vol. 32, pp. 636-643, 2005.
11.Foldy, L. L., “The multiple scattering of waves,” Phys. Rev., Vol. 67, pp. 107-119, 1945.
12.Friedlander, B., B. Porat, “Detection of transient signals by the Gabor representation,” IEEE Trans. Acoust. Speech Signal Process., Vol. 37, pp. 169-180, 1989.
13.Farmer, D. M., C. L. McNeil, and B. D. Johnson, “Evidence of the importance of bubbles in increasing air-sea gas flux,” Nature, Vol. 361, pp. 620-623, 1993.
14.Friedlander, B., A. Zeira, “Oversampled Gabor representation for transient signals,” IEEE Trans. Signal Process., Vol. 43, pp. 2088-2094, 1995.
15.Gabor, D., “Theory of communication,” J. I. E. E., Vol. 93, pp. 429-459, 1946.
16.Guo. J. J., L. Tsang, W. E. Asher, K. H. Ding, and C. T. Chen, “Applications of dense media radiative transfer theory for passive microwave remote sensing of foam covered ocean,” IEEE Trans. Geoscience and Remote Sensing, Vol. 39, No. 5, pp. 1019-1027, 2001.
17.Hwang, P. A., Y.-H. L. Hsu, J. Wu, “Air bubbles produced by breaking wind waves,” J. Phys. Oceangr., 20, pp. 19-28, 1990.
18.Huang, C. J., Dong, C. M., “Wave deformation and vortex generation in water waves propagating over a submerged dike,” Coast. Eng., Vol. 37, pp. 123-148, 1999.
19.Hong, M., Cartellier, A., Hopfinger, E. J., “Characterization of phase detection optical probes for the measurement of the dispersed phase parameters in sprays,” Int. J. Multiphase Flow, Vol. 30, pp. 615-648, 2004.
20.Ishii, M., Thermo- Fluid Dynamic Theory of Two-Phase Flow， Eyrolles, Paris, France, 1975.
21.Johnson, B. D. and R. C. Cooke, “Bubble populations and spectra in coastal waters：A photographic approach,” J. Geophys. Res., Vol. 84, pp. 3761-3766, 1979.
22.Juliá, J. E., W. K. Harteveld, R. F. Mudde, H. E. A. Van den Akker, “On the accuracy of the void fraction measurements using optical probes in bubbly flows,” Rev. Sci. Instrum., Vol. 76, , pp. 1- 13, 2005.
23.Kiambi, S. L., A. M. Duquenne, A. Bascoul, H. Delmas, “Measurements of local interfacial area：Application of bi-optical fibre technique,” Chem. Eng. Sci., Vol. 56, pp. 6447-6453, 2001.
24.Leighton, T. G., Fagan, K. J., Field, J. E., “Acoustic and photographic studies of injected bubbles,” Eur. J. Phys., Vol. 12, pp. 77-85, 1991.
25.Leighton, T. G., P. R. White, M. F. Schneider, “The detection and dimension of bubble entrainment and comminution,” J. Acoust. Soc. Am., Vol. 103, No. 4, pp. 1825-1835, 1998.
26.Minnaert, M., “On musical air-bubbles and the sounds of running water,” Phil. Mag. Vol. 16, pp. 235-248, 1933.
27.Morris, D., A. Teyssedou, J. Lapierre, A. Tapucu, “Optical fiber probe to measure local void fraction profiles,” Appl. Opt., Vol. 26, No. 21, pp. 4660-4664, 1987.
28.Medwin, H., Breitz, N. D., “Ambient and transient bubble spectral densities in quiescent seas and upper spilling breakers,” J. Geophys. Res., Vol. 94, No. C9, pp. 12,751-12,759, 1989.
29.Medwin, H. and A. C. Daniel, “Acoustical measurements of bubble production by spilling breakers,” J. Acoust. Soc. Am., Vol. 88, pp. 408-412, 1990.
30.Panton, R. L., Incompressible Flow, John Wiley and Sons, New York, NY., USA 1984.
31.Pumphrey, H. C., Crum, L. A., “Underwater sound produced by individual drop impacts and rainfall,” J. Acoust. Soc. Am., Vol. 58, pp. 1518-1526, 1989.
32.Silberman, E., “Sound velocity and attenuation in bubbly in water,” J. Fluid Mech., Vol.1, pp. 249-275, 1957.
33.Su, M. Y., Todoroff, D., Cartmill, J., “Laboratory comparisons of acoustic and optical sensors for microbubble measurement,” J. Atoms. Oceanic Tech., Vol.11, No. 1, pp. 170-181, 1994.
34.Sabri, S., K. Shakourzadeh, D. Bastoul, and J. Militzer, “Bubble size and velocity measurement in gas-liquid systems：Application of fibre optic technique to pilot plant scale,” The Canadian J. Chem. Eng., Vol. 73, pp. 253-257, 1995.
35.Serdula, C. D., M. R. Loewen, “Experiments investigating the use of fiber-optic probes for measuring bubble-size distributions,” J. Oceanic Eng., Vol. 23, No. 4, pp. 385-399, 1998.
36.Ting, F. C. K., Kim, Y. K., “Vortex generation in water waves propagating over a submerged obstacle,” Coast. Eng., Vol. 24, pp. 23-49, 1994.
37.Wu, J., “Films drops produced by air bubbles bursting at the surface of seawater,” J. Geophys. Res., No. c8, pp. 16403-16407, 1994a.
38.Wu, J., “Bubbles in the near-surface ocean,” J. Phys. Oceangr., Vol. 24, pp. 1955- 1965, 1994b.
39.許世盛，(2000)，「近岸碎波產生氣泡之特性」，國立成功大學水利及海洋工程研究所碩士論文。(指導教授 黃清哲)。
40.李建勳、黃清哲、林武文，(2007)，「光纖量測氣泡體積分率之研究」，第九屆水下技術研討會，106-113頁。