本實驗旨在探討超音波作用於水中，其誘導流場之觀察與測量。利用紋影法不干涉流場、且可範圍觀察的特性，觀察超音波聲束，藉此測得超音波在不同驅動電壓下，其聲束的聲束寬、焦點聲束寬、焦點面積、以及焦點位置。此外，利用天平在不干擾流場的狀況下，量測超音波作用於水中，且不同驅動電壓所產生之作用力。而結合以上兩個實驗之結果，可進一步推得超音波在不同驅動電壓下，其聲束焦點之平均壓力、平均聲強、平均功率。

This study is to observe and to measure the flow field in the water induced by an ultrasound. Based on the characters of schlieren method, without disturbing the flow field and having a large field of view, the ultrasound beam induced flow field in the water is observed. By this method, the beamwidth, beamwidth of the focus, focus area, and the position of focus have been observed and measured in various ultrasound driving voltage. Following with a special designed balance system to measure the force produced by the probe under different driving voltage in the water. Combine both of the measurement and observation results of the previous two experiments the mean pressure, mean intensity, and mean power of the focus of beam have been obtained.

【1】C. V. Raman and N. S. Nagendra Nathe, ” The diffraction of light by high
frequency sound waves: Part I.” Proceedings Mathematical Sciences,
Vol. 2, N0. 4, Oct. 1935
【2】W.E. Moore and J.A. Bucaro,” Measurement of acoustic fields using
schlieren and holographic techniques” Acoust. Soc. Am., Journal, vol. 63,
Jan. 1978, p. 60-67
【3】J. A. Bucaro; H. D. Dardy,”Sensitivity of the schlieren method for the
visualization of low-frequency ultrasonic waves”,Acoust. Soc. Am.,
Journal, vol. 63, Mar. 1978, p. 768-773.
【4】B. Porter,”Quantitative real-time schlieren system for ultrasound
visualization”,Review of Scientific Instruments, Volume 55, Issue 2,
February 1984, pp.216-221
【5】A.Hanafy and C.I. Zanelli,”Quantitative Real-Time Pulsed Schlieren
Imaging of Ultrasonic Waves”, Ultrasonics Syposium, IEEE 1991,
pp1223-1227.
【6】Todd A. Pitts, James F. Greenleaf, Jian-yu Lu, and Randy R. Kinnick,”
Tomographic Schlieren Imaging for Measurement of Beam Pressure and
Intensity”, Ultrasonics Syposium, IEEE 1994, pp1665-1668.
【7】Claudio I. Zanelli and Samuel M. Howard,”Schlieren metrology for high
frequency medical ultrasound”, Ultrasonics,Vol. 44, Supplement 1, 22
Dec. 2006, pp 105-107
【8】Gerald R. Harris, “Hydrophone Measurements in Diagnostic Ultrasound
Fields”, IEEE Transactions on Ultrasonics. Ferroelectrics. And Frequency
Control, Vol.35, No.2 ,Mar. 1988.
【9】Byron Schneider and K. Kirk Shung, ”Quantitative Analysis of Ultrasonic
Beam Patterns Using a Schlieren System”, IEEE Transactions on
Ultrasonics. Ferroelectrics. And Frequency Control, Vol.43, No.6 ,Nov.
1996.
【10】John Lekner, ”Acoustic beam invariants”, The American Physical Society
2007.
【11】 Yuebing Wang; Fangwei Ye, ”The Measurement of HIFU Field Using a
Reflective Needle Hydrophone”, 6th Intenational Symposium on
Theapeutic Ultrasound. AIP Conference Proceedings, Vol. 911, pp. 3-7,
2007.
【12】G. S. Settles, ”Color schlieren optics-A review of techniques and
applications”, Proc. ISFV 2, Bochum, 1980, W. Merzkirch(Ed)
Hemispere, Wash., pages 749–759, 1982.
【13】G. S. Settles, ”Colour-coding schlieren techniques for the optical study of
heat and fluid flow”,Int. J. Heat & Fluid Flow, Vol. 6, No. 1, March
1985.
【14】G. S. Settles, ”Modern Developments in Flow Visualization”, AIAA J.,
Vol. 24, No. 8, Aug. 1986.
【15】P. S. Greenberg, , R.B.Klimek, , D.R. Buchele, ,” Quantitative Rainbow
Schlieren Deflectometry”, Applied Optics, Optical Society of America,
Washington, DC, Vol. 34 (19), pp. 3810-3822, July, 1995.
【16】J. Lubbers and R. Graaff ,” A simple and accurate formula for the sound
velocity in water”, Ultrasound in medicine & biology 24(7), Sep.
1998,pp1065-8
【17】Lawrence E. Kinsler, Austin R. Frey, Alan B. Coppens, James V.
Saners, “Fundamentals of Acoustic”, 3rd edition, John Wiley & Sons,
New York.
【18】Allan D. Pierce, “Acoustics: An Introduction to Its Physical Principle and
Application”, McGraw-Hill Book Cop., New York.
【19】白明憲, “工程聲學”,全華圖書股份有限公司.
【20】R.J. Goldstein, “Fluid Mechanics Measurements”, Second edition, Taylor & Francis publishers, University of Minnesota, pp. 451-474, 1996.