Determination of Void Fraction by Image Processing

Öz

Void fraction is one of the key parameters for defining the characteristics of a two phase flow. However, determination of void fraction is not easy due to changing conditions of flow and the type of fluid. In literature, there are plenty of works on determination of void fraction in two-phase flow in a pipe or channel which uses psychical parameters and properties of the system, flow and fluid. Since there are plenty number of correlations for various flow types, an experimental method has been suggested to determine the void fraction according to flow type without using any physical parameter of the flow and fluid. Image visualization methods have been applied to two-phase flow of refrigerant R600a in a circular tube. The images from high speed photography have been processed using a software developed with MATLAB Image Processing Toolbox.  The results were also compared with the well-known correlations.

Anahtar Kelimeler

• Image processing,Two-phase flow,Void fraction

BOŞLUK ORANININ GÖRÜNTÜ İŞLEME YARDIMIYLA BULUNMASI

Öz

Boşluk oranı iki fazlı akışta akışın karakterini tanımlamak için kullanılan önemli parametrelerden biridir. Bununla beraber değişken akış koşulları ve akış türü nedeniyle boşluk oranını belirlemek çok kolay değildir. Literatürde bir boru veya kanal içinde boşluk oranını tanımlama üzere sistem, akış ve akışkan ile ilgili parametreleri kullanan pek çok model bulunmaktadır. Farklı akış tipleri için pek çok korelasyon bulunduğu için bu çalışmada akışla ilgili herhangi bir parametre kullanmayan bir deneysel yöntem önerilmiştir.  Görüntü işleme yöntemi R600a akışkanının dairesel bir boru içerisinde iki fazlı akışına uygulanmıştır. Yüksek hızlı kamera ile elde edilen görüntüler MATLAB görüntü işleme aracını kullanarak geliştirilen bir yazılımda işlenmiştir. Ayrıca sonuçlar literatürde sık kullanılan korelasyonlarla karşılaştırılmıştır.

Anahtar Kelimeler

• Görüntü işleme,İki fazlı akış,Boşluk oranı

Kaynakça

1. Armand A.A. and Treschev, G.G. (1946) The Resistance During the Movement of a Two-phase System in Horizontal Pipes, IzvestiaVse Teplotekh. Inst.,1, 16–23.
2. Baroczy C.J., (1965) Correlation of liquid fraction in two-phase flow with application to liquid metals, Chemical Engineering Progress Symposium Series, 61 (57), 179–191.
3. Bowers, C. D. and Hrnjak, P. S. (2010) Determination of Void Fraction in Separated Two-Phase Flows Using Optical Techniques, International Refrigeration and Air Conditioning Conference, Paper 1083. http://docs.lib.purdue.edu/iracc/1083
4. Cavallini, A., El-Hajal, J. and Thome, J. R. (2003) Condensation in horizontal tubes, part 1: two-phase flow pattern, part 2: new heat transfer model based on flow regimes, International Journal of Heat and Mass Transfer, 46, 3349-3363. doi:10.1016/S0017-9310(03)00139-X, doi:10.1016/S0017-9310(03)00140-6
5. El-Hajal J. and Fauske H. (1961) Critical two-phase, steam-water flows, Proceedings of the Heat Transfer and Fluid Mechanics Institute, Stanford University Press, Stanford, CA, 79–89.
6. Godbole, P. V., Tang, C. C. and Ghajar, A. J. (2011) Comparison of Void Fraction Correlations for Different Flow Patterns in Upward Vertical Two-Phase Flow, Heat Transfer Engineering, 32, 843-860. doi:10.1080/01457632.2011.548285
7. Hibiki, T. and Mishima, K. (1996) Feasibility of high frame-rate neutron radiography by using a steady thermal neutron beam with 106 n/(cm2 s) flux, Nuclear Instruments and Methods in Physics Research, A369, 186-194. doi:10.1016/0168-9002(95)00795-4
8. Hibiki, T., Mishima, K. and Nishihara, H. (1997) Measurement of radial void fraction distribution of two-phase flow in a metallic round tube using neutrons as microscopic probes, Nuclear Instruments and Methods in Physics Research, A399, 432-438. doi:10.1016/S0168-9002(97)00941-8

9. Kariyasaki, A., Fukano, T., Ousaka, A. and Kagawa, M. (1991) Characteristics of time-varying void fraction in isothermal air-water concurrent flow in a horizontal capillary tube, Trans. JSME, 57, 4036-4043
10. Kawahara A., Kawaji, M., Chung, P.M.Y., Sadatomi, M. and Okayama K. (2005) Effects of channel diameter and liquid properties on void fraction in adiabatic two-phase flow through microchannels, Heat Transfer Engineering, 26, 13–19. doi:10.1080/01457630590907158
11. Koyama S., Lee, J. and Yonemoto, R. (2004) An investigation on void fraction of vapor-liquid two-phase flow for smooth and microfin tubes with R134a at adiabatic condition, International Journal of Multiphase Flow, 30, 291-310. doi:10.1016/j.ijmultiphaseflow.2003.10.009
12. Lockhart, R.W. and Martinelli R.C. (1949) Proposed correlation of data for isothermal twophase, two-component flow in pipes, Chemical Engineering Progress, 45, 39–48. http://www.ripublication.com/ijaer17/ijaerv12n7_23.pdf
13. Mishima, K. and Hibiki, T. (1996), Some characteristics of air-water two-phase flow in small diameter vertical tubes, Int. J. of Multiphase Flow, 22, 701-703. doi:10.1016/0301-9322(96)00010-9
14. Mishima, K., Hibiki, T. and Nishihara, H. (1997) Visualization and measurement of two-phase flow by using neutron radiography, Nuclear Engineering and Design, 175, 25-35. doi:10.1016/S0029-5493(97)00159-3
15. Premoli, A., Francesco, D. and Prima, A. (1971) An empirical correlation for evaluating twophase mixture density under adiabatic conditions, European Two-Phase Flow Group Meeting, Milan, Italy.
16. Saisorn, S. and Wongwises, S. (2009) An experimental investigation of two-phase air–water flow through a horizontal circular micro-channel, Experimental Thermal and Fluid Science, 33, 306-315. doi:10.1016/j.expthermflusci.2008.09.009
17. Smith S. J., Shao L. and Riffat S. B. (2001) Pressure drop of HFC refrigerants inside evaporator and condenser coils as determined by CFD, Applied Energy, 70, 169-178. doi:10.1016/S0306-2619(01)00022-8
18. Tandon T. N., Varma H. K. and Gupta C. P. (1985) A void fraction model for annular two-phase flow, International Journal of Heat Mass Transfer, 28, 191-198. doi:10.1016/0017-9310(85)90021-3
19. Thom J.R.S. (1964) Prediction of pressure drop during forced circulation boiling of water, International Journal of Heat and Mass Transfer, 7, 709–724. doi:10.1016/0017-9310(64)90002-X
20. Thome J.R (2004-2006) Engineering Data Book III, Wolverine Tube Inc.
21. Thome J.R. (2005) Condensation in plain horizontal tubes: Recent advances in modelling of heat transfer to pure fluids and mixtures, Journal of the Braz. Soc. of Mech. Sci.&Eng., 27, 23-30. http://www.scielo.br/pdf/jbsmse/v27n1/25373.pdf
22. Thome J.R. (2005) Update on advances in flow pattern based two phase heat transfer models, Experimental Thermal and Fluid Science, 29(3), 341-349. doi:10.1016/j.expthermflusci.2004.05.015
23. Thome J.R., Ould Didi, M.B. and Kattan N. (2002) Prediction of two phase pressure gradients of refrigerants in horizontal tubes, International Journal of Refrigeration, 25, 935-947. doi:10.1016/S0140-7007(01)00099-8
24. Triplett, K. A., Ghiaasiaan, S.M., Abdel-Khalik, S.I. and Sadowski, D.L. (1999) Gas-liquid two-phase flow in microchannels,Part I: Two-phase flow patterns, International Journal of Multiphase Flow, 25, 377-394. doi:10.1016/S0301-9322(98)00054-8
25. Winkler, J., Killion, J. and Srinivas G. (2012) Void fractions for condensing refrigerant flow in small channels. Part II: Void fraction measurement and modeling, International Journal of Refrigeration, 35, 246-262. doi:10.1016/j.ijrefrig.2011.08.012
26. Winkler, J., Killion, J., Srinivas G. and Fronk, B. M. (2012) Void fractions for condensing refrigerant flow in small channels: Part I literature review, International Journal of Refrigeration, 35, 219-245. doi:10.1016/j.ijrefrig.2011.09.013
27. Yashar, D. A., Newell, T. A. and Chato, J. C. (1998) Experimental investigation of void fraction during horizontal flow in smaller diameter refrigeration applications, ACRC TechnicalReport141.https://www.ideals.illinois.edu/bitstream/handle/2142/11849/TR140.pdf?sequence=2
28. Zivi S.M. (1964) Estimation of steady-state steam void-fraction by means of the principle of minimum entropy production, Transactions ASME Journal of Heat Transfer Series C, 86, 247–252. doi:10.1115/1.3687113