© 2022 IIETA. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).
OPEN ACCESS
Annular gas–liquid flows have been extensively studied over the years. However, the nonlinear behavior of the interface is still currently the subject of study by multiple researchers worldwide. The appearance of a liquid layer on the wall and its turbulent behavior support the heat exchange of multiple systems in the industrial field. Research in this area allows the optimization of these installations as well as the analysis of possible safety problems if the liquid film disappears. This study first shows some of the most important findings obtained in the GEPELON experimental facility (GEneración de PElícula ONdulatoria or Wavy Film Generator). The facility was built in order to analyze the behavior of the liquid film in annular downward air–water flow. The experimental range of the inlet conditions is 800–8000 for the ReL and 0–110,000 for the Reg. Measurements for the mean film thickness show a fairly good agreement with the empirical correlations and the measurements of other authors. One of the most demanded applications of this type of measurements is the validation of computational dynamics or CFD codes. Therefore, the experiment has been modeled using Ansys CFX software, and the simulation results have been compared with the experimental ones. This article outlines some of the reasons why two-phase flow simulations are currently challenging and how the codes are able to overcome them. Simulation predictions are fairly close to the experimental measurements, and the mean film thickness evolution when changing the boundary conditions also shows a good agreement.
CFD simulation, conductance probe, experimental measurements, film thickness, vertical downward annular flow
[1] Hanratty, T.J. & Hershman, A., Initiation of roll waves. AIChE Journal, 7, pp. 488–497, 1961. https://doi.org/10.1002/aic.690070330
[2] Hall Taylor, N.S., Hewitt, I.J., Ockendon, J.R. & Witelski, T.P., A new model for disturbance waves. International Journal of Multiphase Flow, 66, pp. 38–45, 2014. https://doi.org/10.1016/J.IJMULTIPHASEFLOW.2014.06.004
[3] Alekseenko, S.V., Antipin, V.A., Cherdantsev, A.V., Kharlamov, S.M. & Markovich, D.M., Investigation of waves interaction in annular gas-liquid flow using high-speed fluorescent visualization technique. Microgravity Science and Technology, 20, pp. 271–275, 2008. https://doi.org/10.1007/s12217-008-9028-1
[4] Alekseenko, S.V., Cherdantsev, A.V., Cherdantsev, M.V., Isaenkov, S.V. & Markovich, D.M., Study of formation and development of disturbance waves in annular gas-liquid flow. International Journal of Multiphase Flow, 77, pp. 65–75, 2015. https://doi.org/10.1016/j.ijmultiphaseflow.2015.08.007
[5] Wolf, A., Film Structure of Vertical Annular Flow, Imperial College of Science, Technology and Medicine. London University, 1995.
[6] Schubring, D., Ashwood, A.C., Shedd, T.A. & Hurlburt, E.T., Planar laser-induced fluorescence (PLIF) measurements of liquid film thickness in annular flow. Part I: Methods and data. International Journal of Multiphase Flow, 36, pp. 815–824, 2010. https://doi.org/10.1016/j.ijmultiphaseflow.2010.05.007
[7] Belt, R.J., Van’t Westende, J.M.C., Prasser, H.M. & Portela, L.M., Time and spatially resolved measurements of interfacial waves in vertical annular flow. International Journal of Multiphase Flow, 36, pp. 570–587, 2010. https://doi.org/10.1016/j.ijmultiphaseflow.2010.03.004
[8] Berna, C., Escrivá, A., Muñoz-Cobo, J.L. & Herranz, L.E., Review of droplet entrainment in annular flow: Interfacial waves and onset of entrainment. Progress in Nuclear Energy, 74, pp. 14–43, 2014. https://doi.org/10.1016/j.pnucene.2014.01.018
[9] Berna, C., Escrivá, A., Muñoz-Cobo, J.L. & Herranz, L.E., Review of droplet entrainment in annular flow: Characterization of the entrained droplets. Progress in Nuclear Energy, 79, pp. 64–86 2015. https://doi.org/10.1016/j.pnucene.2014.11.011
[10] Setyawan, A., Indarto, Deendarlianto, The effect of the fluid properties on the wave velocity and wave frequency of gas-liquid annular two-phase flow in a horizontal pipe. Experimental Thermal and Fluid Science, 71, pp. 25–41, 2016. https://doi.org/10.1016/j.expthermflusci.2015.10.008
[11] Nusselt, W., Die oberflächenkondensation des wasserdampfes. Zeitschrift Des Vereines Dtsch. Ingenieure, 60, pp. 541–546 (no27) and pp. 569–575 (no 28), 1916.
[12] Takahama, H. & Kato, S., Longitudinal flow characteristics of vertically falling liquid films without concurrent gas flow. International Journal of Multiphase Flow, 6,pp. 203–215, 1980. https://doi.org/10.1016/0301-9322(80)90011-7
[13] Mudawwar, I.A. & El-Masri, M.A., Momentum and heat transfer across freely-falling turbulent liquid films. International Journal of Multiphase Flow, 12, pp. 771–790, 1986. https://doi.org/10.1016/0301-9322(86)90051-0
[14] Karapantsions, T.D., Paras, S.V. & Karabelas, A.J., Statistical characteristics of free falling films at high Reynolds numbers. International Journal of Multiphase Flow, 15, pp. 1–21, 1989. https://doi.org/10.1016/0301-9322(89)90082-7
[15] Karimi, G. & Kawaji, M., An experimental study of freely falling films in a vertical tube. Chemical Engineering Science, 53, pp. 3501–3512, 1998. https://doi.org/10.1016/S0009-2509(98)00159-6
[16] Zadrazil, I., Matar, O.K. & Markides, C.N., An experimental characterization of downwards gas-liquid annular flow by laser-induced fluorescence: Flow regimes and film statistics. International Journal of Multiphase Flow, 60, pp. 87–102, 2014. https://doi.org/10.1016/j.ijmultiphaseflow.2013.11.008
[17] Cherdantsev, A.V., An, J.S., Charogiannis, A. & Markides, C.N., Simultaneous application of two laser-induced fluorescence approaches for film thickness measurements in annular gas-liquid flows. International Journal of Multiphase Flow, 119, pp. 237–258, 2019. https://doi.org/10.1016/j.ijmultiphaseflow.2019.07.013
[18] Charogiannis, A., Sik An, J., Voulgaropoulos, V. & Markides, C.N., Structured planar laser-induced fluorescence (S-PLIF) for the accurate identification of interfaces in multiphase flows. International Journal of Multiphase Flow, 118, pp. 193–204, 2019. https://doi.org/10.1016/j.ijmultiphaseflow.2019.06.002
[19] Smith, B.L., Assessment of CFD for NRS, OECD/NEA IAEA Work, 2008.
[20] Mahaffy, J., Chung, B., Dubois F., Ducros, F., Graffard, E., Heitsch, M., Henriksson, M., Komen, E., Moretti, F., Morii, T., Mühlbauer, P., Rohde, U., Scheuerer, M., Smith, B.L., Song, C., Watanabe, T. & Zigh, G., Best Practice Guidelines for the Use of CFD in Nuclear Reactor Safety Applications, 2014.
[21] Rivera, Y., Muñoz-Cobo, J.L., Berna, C., Escrivá, A. & Cordova, Y., Study of liquid film behaviour in vertical downward air–water annular flow. Advances in Fluid Mechanics XIII, pp. 77–88, 2020. https://doi.org/10.1115/1.3138339
[22] Clark, W.W.P., The interfacial characteristics of falling film reactors, pp. 1–328, 2001. http://eprints.nottingham.ac.uk/14303/ (accessed September 5, 2018)
[23] Collier, J.G. & Hewitt, G., Data on the vertical flow of air-water mixtures in the annular and dispersed flow regions, Part II: Film thickness and entrainment data and analysis of pressure drop measurements. Trans. Inst. Chem. Eng. 37, pp. 127–136, 1961.
[24] Telles, A.S. & Dukler, A.E., Statistical characteristics of thin, vertical, wavy, liquid films. Industrial & Engineering Chemistry Fundamentals, 9, pp. 412–421, 1970. https://doi.org/10.1021/i160035a018
[25] Fukano, T., Measurement of time varying thickness of liquid film flowing with high speed gas flow by a constant electric current method (CECM). Nuclear Engineering and Design, 184, pp. 363–377, 1998. https://doi.org/10.1016/S0029-5493(98)00209-X
[26] Zhao, Y., Markides, C.N., Matar, O.K. & Hewitt, G.F., Disturbance wave development in two-phase gas–liquid upwards vertical annular flow. International Journal of Multiphase Flow, 55, pp. 111–129, 2013. https://doi.org/10.1016/J.IJMULTIPHASEFLOW.2013.04.001
[27] Ghosh, S., Pratihar, D.K., Maiti, B. & Das, P.K., Automatic classification of vertical counter-current two-phase flow by capturing hydrodynamic characteristics through objective descriptions. International Journal of Multiphase Flow, 52, pp. 102–120, 2013. https://doi.org/10.1016/j.ijmultiphaseflow.2012.12.007
[28] Muñoz-Cobo, J., Chiva, S., Méndez, S., Monrós, G., Escrivá, A., Cuadros, J., Muñoz-Cobo, J.L., Chiva, S., Méndez, S., Monrós, G., Escrivá, A. & Cuadros, J.L., Development of conductivity sensors for multi-phase flow local measurements at the polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI). Sensors, 17, p. 1077, 2017. https://doi.org/10.3390/s17051077
[29] Rivera, Y., Muñoz-Cobo, J.L., Cuadros, J.L., Berna, C. & Escrivá, A., Experimental study of the effects produced by the changes of the liquid and gas superficial velocities and the surface tension on the interfacial waves and the film thickness in annular concurrent upward vertical flows. Experimental Thermal and Fluid Science, 120, 2021. https://doi.org/10.1016/j.expthermflusci.2020.110224
[30] Canonsburg, T.D., ANSYS meshing user’ s guide. Knowl. Creat. Diffus. Util, 15317, pp. 724–746, 2011.
[31] Simoneau, J.-P., Champigny, J. & Gelineau, O., Applications of large eddy simulations in nuclear field. Nuclear Engineering and Design, 240, pp. 429–439, 2010. https://doi.org/10.1016/j.nucengdes.2008.08.018
[32] Iglesias, S.M., Dominguez, D.S., Escrivá, A., Muñoz-Cobo, J.L., Berna, C., Cuadros, J.L. & Rivera, Y., Computational fluid dynamics applied to the study of falling liquid films in a wave film generation facility. Proc. 6th Eur. Conf. Comput. Mech. Solids, Struct. Coupled Probl. ECCM 2018 7th Eur. Conf. Comput. Fluid Dyn. ECFD 2018, 2020.
[33] Fan, W., Cherdantsev, A.V. & Anglart, H., Experimental and numerical study of formation and development of disturbance waves in annular gas-liquid flow. Energy, 207,p. 118309, 2020. https://doi.org/10.1016/j.energy.2020.118309
[34] Webb, D.R. & Hewitt, G.F., Downwards co-current annular flow. International Journal of Multiphase Flow, 2, pp. 35–49, 1975. https://doi.org/10.1016/0301-9322(75)90027-0
[35] Karapantsios, T.D. & Karabelas, A.J., Longitudinal characteristics of wavy falling films. International Journal of Multiphase Flow, 21, pp. 119–127, 1995. https://doi.org/10.1016/0301-9322(94)00048-o