本研究自製Laskin nozzle作為氣溶膠產生器之霧化器，將其產生的橄欖油氣溶膠利用Malvern Spraytec粒徑分析儀進行粒徑的量測，以證實Laskin nozzle能產生粒徑約1至2 μm的粒子，並可提供至PIV實驗中做為示蹤粒子。本實驗會考量以下條件對粒子特性造成的影響，分別為Laskin nozzle進氣壓力的變化、噴嘴的幾何變化與加工誤差、氣溶膠產生器之出煙管長度以及出口型態，在每個條件下量測氣溶膠的粒徑與濃度並進行結果探討，以避免氣溶膠粒子產生不同尺寸的粒徑分布而影響到PIV的分析結果。
結果顯示Laskin nozzle之進氣壓力對氣溶膠粒徑分布是否集中影響不大，但對平均粒徑與濃度高低有明顯影響：進氣壓力與氣溶膠平均粒徑呈反比，但與氣溶膠濃度呈正比。而Laskin nozzle的噴氣孔徑大小與含有進料孔之平行環設計皆對粒徑量測結果有影響，愈大的噴氣孔會使氣溶膠粒子平均粒徑愈大，但噴氣孔同為1 mm的Laskin nozzle上的加工誤差對粒子特性不會造成太大的影響。在氣溶膠產生器方面，本研究發現出煙管長度對粒徑分布及平均粒徑結果並無造成明顯地差異，因此我們可以選用任一種長度的出煙管進行氣溶膠的製造，而不會影響產出之氣溶膠粒子的特性。最後是氣溶膠產生器之出口型態，若採直接排出法會量測到兩種粒徑尺寸的粒子群，分別為粒徑約1~2 μm之間以及6~8 μm之間的粒子。由於尺寸一致性愈高的示蹤粒子，對於PIV才有愈準確的分析結果，本研究為避免兩種大小粒子群的出現，採用排列式孔洞管作為氣溶膠產生器之出口設置，並觀察氣溶膠之平均粒徑及粒徑分布狀況，發現並無兩種粒徑尺寸的粒子群出現，僅有1~2 μm之間的粒子產生。故本研究自製Laskin nozzle能產生平均粒徑在2 μm之氣溶膠，且可提供至PIV實驗中做為示蹤粒子。

In this study, the self-made Laskin nozzle was used as the atomizer of the aerosol generator, and the olive oil aerosol produced by it was measured by the Malvern Spraytec particle size analyzer. At the same time, the influence of different conditions on the characteristics of the particles is considered, to avoid the aerosol particles with different sizes affect the future PIV analysis results. The results show that the inlet pressure of the Laskin nozzle has the most obvious influence on the Sauter mean diameter (SMD) and volume concentration (Cv) under the same nozzle hole size of 1mm: the larger the inlet pressure, the smaller the SMD, and the greater the Cv. The self-made Laskin nozzle of this research can produce particles with a particle size of 1 to 2 μm, which can be used as tracer particles in the PIV experiments.

[1] Y.-T. Wu, C.-Y. Lin, and C.-M. Hsu, "An Experimental Investigation of Wake Characteristics and Power Generation Efficiency of a Small Wind Turbine under Different Tip Speed Ratios," Energies, vol. 13, no. 8, p. 2113, 2020.
[2] A. Melling, "Tracer particles and seeding for particle image velocimetry," Measurement Science and Technology, vol. 8, no. 12, pp. 1406-1416, 1997/12/01 1997.
[3] C. Kähler, B. Sammler, and J. Kompenhans, "Generation and control of tracer particles for optical flow investigations in air," Experiments in fluids, vol. 33, no. 6, pp. 736-742, 2002.
[4] R. P. Bauman and R. Schwaneberg, "Interpretation of Bernoulli’s equation," The Physics Teacher, vol. 32, no. 8, pp. 478-488, 1994.
[5] L. Kristensen, "Cup anemometer behavior in turbulent environments," Journal of Atmospheric and Oceanic Technology, vol. 15, no. 1, pp. 5-17, 1998.
[6] G. P. Russo, "3 - Hot wire anemometer," in Aerodynamic Measurements, G. P. Russo Ed.: Woodhead Publishing, 2011, pp. 67-98.
[7] R. Klopfenstein Jr, "Air velocity and flow measurement using a Pitot tube," ISA transactions, vol. 37, no. 4, pp. 257-263, 1998.
[8] J. Chen, B. S. Haynes, and D. F. Fletcher, "Cobra probe measurements of mean velocities, Reynolds stresses and higher-order velocity correlations in pipe flow," Experimental Thermal and Fluid Science, vol. 21, no. 4, pp. 206-217, 2000/05/01/ 2000.
[9] M. Raffel, C. E. Willert, F. Scarano, C. J. Kähler, S. T. Wereley, and J. Kompenhans, Particle image velocimetry: a practical guide. Springer, 2018.
[10] B. Chu, Laser light scattering: basic principles and practice. Courier Corporation, 2007.
[11] A. Goharzadeh and A. Molki, "Measurement of fluid velocity development behind a circular cylinder using particle image velocimetry (PIV)," European Journal of Physics, vol. 36, no. 1, p. 015001, 2014.
[12] J. C. Schatzman, "A model for the von Kármán vortex street," California Institute of Technology, 1981.
[13] J. Westerweel, G. E. Elsinga, and R. J. Adrian, "Particle image velocimetry for complex and turbulent flows," Annual Review of Fluid Mechanics, vol. 45, pp. 409-436, 2013.
[14] S. Scharnowski, M. Bross, and C. J. Kähler, "Accurate turbulence level estimations using PIV/PTV," Experiments in Fluids, vol. 60, no. 1, pp. 1-12, 2019.
[15] C. M. McNiel, D. W. Peltier, M. F. Reeder, and J. W. Crafton, "Clean Seeding for Particle Image Velocimetry," in 2007 22nd International Congress on Instrumentation in Aerospace Simulation Facilities, 10-14 June 2007 2007, pp. 1-6.
[16] F. Crosswy, "Particle size distributions of several commonly used seeding aerosols," Wind Tunnel Seeding Systems for Laser Velocimeters, pp. 53-75, 1985.
[17] Z. B. Tong, R. Y. Yang, K. W. Chu, A. B. Yu, S. Adi, and H. K. Chan, "Numerical study of the effects of particle size and polydispersity on the agglomerate dispersion in a cyclonic flow," Chemical Engineering Journal, vol. 164, no. 2, pp. 432-441, 2010/11/01/ 2010.
[18] R. Poon, P. Lecavalier, R. Mueller, V. Valli, B. Procter, and I. Chu, "Subchronic oral toxicity of di-n-octyl phthalate and di (2-ethylhexyl) phthalate in the rat," Food and Chemical Toxicology, vol. 35, no. 2, pp. 225-239, 1997.
[19] K. T. Lowe, G. Byun, and R. L. Simpson, "The effect of particle lag on supersonic turbulent boundary layer statistics," in 52nd Aerospace Sciences Meeting, 2014, p. 0233.
[20] T. R. Bewley, P. Moin, and R. Temam, "DNS-based predictive control of turbulence: an optimal benchmark for feedback algorithms," Journal of Fluid Mechanics, vol. 447, no. 2, pp. 179-225, 2001.
[21] W. Hinds, J. Macher, and M. First, "Size distribution of aerosols produced by the Laskin aerosol generator using substitute materials for DOP," American Industrial Hygiene Association Journal, vol. 44, no. 7, pp. 495-500, 1983.
[22] D. Rabe and K. Sabroske, "Laskin nozzle performance for laser flow measurement seeding," in 32nd Aerospace Sciences Meeting and Exhibit, 1994, p. 44.
[23] S. Slomkowski, J. V. Alemán, R. G. Gilbert, M. Hess, K. Horie, R. G. Jones, P. Kubisa, I. Meisel, W. Mormann, and S. Penczek, "Terminology of polymers and polymerization processes in dispersed systems (IUPAC Recommendations 2011)," Pure and Applied Chemistry, vol. 83, no. 12, pp. 2229-2259, 2011.
[24] V. Després, J. A. Huffman, S. M. Burrows, C. Hoose, A. Safatov, G. Buryak, J. Fröhlich-Nowoisky, W. Elbert, M. Andreae, and U. Pöschl, "Primary biological aerosol particles in the atmosphere: a review," Tellus B: Chemical and Physical Meteorology, vol. 64, no. 1, p. 15598, 2012.
[25] P. Roupsard, M. Amielh, D. Maro, A. Coppalle, H. Branger, O. Connan, P. Laguionie, D. Hébert, and M. Talbaut, "Measurement in a wind tunnel of dry deposition velocities of submicron aerosol with associated turbulence onto rough and smooth urban surfaces," Journal of Aerosol Science, vol. 55, pp. 12-24, 2013.
[26] G. W. Gee and D. Or, "2.4 Particle‐size analysis," Methods of soil analysis: Part 4 physical methods, vol. 5, pp. 255-293, 2002.
[27] Z. Ma, H. G. Merkus, J. G. de Smet, C. Heffels, and B. Scarlett, "New developments in particle characterization by laser diffraction: size and shape," Powder Technology, vol. 111, no. 1-2, pp. 66-78, 2000.
[28] G. Eshel, G. Levy, U. Mingelgrin, and M. Singer, "Critical evaluation of the use of laser diffraction for particle‐size distribution analysis," Soil Science Society of America Journal, vol. 68, no. 3, pp. 736-743, 2004.
[29] A. Annapragada and A. Adjei, "An analysis of the fraunhofer diffraction method for particle size distribution analysis and its application to aerosolized sprays," International Journal of Pharmaceutics, vol. 127, no. 2, pp. 219-227, 1996/02/17/ 1996.
[30] W. Hergert and T. Wriedt, The Mie theory: basics and applications. Springer, 2012.
[31] B. ISO, "13320. Particle size analysis-laser diffraction methods," ISO Standards Authority, 2009.
[32] M. J. H. Simmons and T. J. Hanratty, "Droplet size measurements in horizontal annular gas–liquid flow," International Journal of Multiphase Flow, vol. 27, no. 5, pp. 861-883, 2001/05/01/ 2001.
[33] B. Azzopardi, "Drops in annular two-phase flow," International Journal of Multiphase Flow, vol. 23, no. 7, pp. 1-53, 1997.
[34] K. Hay, Z.-C. Liu, and T. Hanratty, "Relation of deposition to drop size when the rate law is nonlinear," International journal of multiphase flow, vol. 22, no. 5, pp. 829-848, 1996.
[35] K. Triballier, C. Dumouchel, and J. Cousin, "A technical study on the Spraytec performances: influence of multiple light scattering and multi-modal drop-size distribution measurements," Experiments in Fluids, vol. 35, no. 4, pp. 347-356, 2003/10/01 2003.
[36] P. E. Santangelo, "Characterization of high-pressure water-mist sprays: Experimental analysis of droplet size and dispersion," Experimental Thermal and Fluid Science, vol. 34, no. 8, pp. 1353-1366, 2010/11/01/ 2010.
[37] A. Radcliffe, "Fuel injection," High Speed Aerodynamics, and Jet Propulsion, vol. 11, p. 84, 1960.
[38] N. Baddoo, "Stainless steel in construction: A review of research, applications, challenges and opportunities," Journal of constructional steel research, vol. 64, no. 11, pp. 1199-1206, 2008.
[39] L. Gardner, "The use of stainless steel in structures," Progress in Structural Engineering and Materials, vol. 7, no. 2, pp. 45-55, 2005.
[40] I. Bodurov, I. Vlaeva, M. Marudova, T. Yovcheva, K. Nikolova, T. Eftimov, and V. Plachkova, "Detection of adulteration in olive oils using optical and thermal methods," Bulgarian Chemical Communications, vol. 45, pp. 81-85, 2013.
[41] C. Peri, The extra-virgin olive oil chain. Wiley Online Library, 2014.
[42] Malvern Panalytical. "Spraytec." Spectris. https://www.malvernpanalytical.com/en/products/product-range/spraytec (accessed 07/21, 2021).
[43] Britannica and The Editors of Encyclopaedia. "Collimator." Encyclopedia Britannica. https://www.britannica.com/technology/collimator (accessed 06/15, 2021).
[44] R. Reitano, C. Faccenna, F. Funiciello, F. Corbi, and S. Willett, Erosional response of granular material in landscape models. 2020.
[45] B. Jennings and K. Parslow, "Particle size measurement: the equivalent spherical diameter," Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, vol. 419, no. 1856, pp. 137-149, 1988.
[46] J. M. Cowley, Diffraction physics. Elsevier, 1995.
[47] D. F. Swinehart, "The beer-lambert law," Journal of chemical education, vol. 39, no. 7, p. 333, 1962.
[48] 張育唐 and 陳藹然. "比爾定律與吸收度." 科學Online. https://highscope.ch.ntu.edu.tw/wordpress/?p=40839 (accessed 06/23, 2021).