OPEN ACCESS
Numerical simulation of the head-on collision of binary equal-sized seawater droplets was conducted by volume of fluid method for tracking the interface and an adaptive mesh for improving the calculation efficiency. In order to reveal the mechanism and the influence factors of seawater droplets in Impinging Seawater Shower Cooling Tower (ISSCT.), veracity of the numerical models was firstly validated with the experimental results of Qian. These outcomes were in good agreement with the experiments. The binary collisions of equal-sized droplets were investigated at various Weber numbers and impact parameters at room temperature and pressure conditions. The Weber number ranged from 0.5 to 200 and the impact parameters ranged from 0 to 1, which covered three different types of outcomes: coalescence, head-on separation and off -centre separation. The results show that the critical Weber number of head-on collisions between coalescence and reflexive separation is 22. The We-x schematic of various collision regimes of seawater droplets is obtained.
adaptive mesh, droplet collision, seawater, VOF method
The financial support of the Nation Natural Science Foundation of China (grant no. 51879154 and 51806128) is acknowledged.
[1] Wei Z, Qi X. (2013). Investigation on equivalent diameter of water droplets in showing cooling tower. Science Technology and Engineering 13(17): 4797-4800.
[2] O'Rourke PJ. (1989). Statistical properties and numerical implementation of a model for droplet dispersion in a turbulent gas. Journal of Computational Physics 83(2): 345-360. https://doi.org/10.1016/0021-9991(89)90123-X
[3] Ashgriz N, Poo JY. (2006). Coalescence and separation in binary collisions of liquid drop. Journal of Fluid Mechanics 221: 183-204. https://doi.org/10.1017/S0022112090003536
[4] Nikolopoulos N, Nikas KS, Bergeles G. (2009). A numerical investigation of central binary collision of droplets. Computers & Fluids 38(6): 1191-1202. https://doi.org/10.1016/j.compfluid.2008.11.007
[5] Nikolopoulos N, Theodorakakos A, Bergeles G. (2009). Off-centre binary collision of droplets: A numerical investigation. International Journal of Heat and Mass Transfer 52(19-20): 4160-4174. https://doi.org/10.1016/j.ijheatmasstransfer.2009.04.011
[6] Qian J, Law CK. (1997). Regimes of coalescence and separation in droplet collision. Journal of Fluid Mechanics 331(01): 59-80. https://doi.org/10.1017/S0022112096003722
[7] Brazier-Smith PR, Jennings SG, Latham J. (1972). The interaction of falling water drops: coalescence. Proceedings of the Royal Society of London 326(1566): 393-408. https://doi.org/10.1098/rspa.1972.0016
[8] Jiang YJ, Umemura A, Law CK. (1992). An experiment investigation on the collision behavior of hydrocarbon droplets. Journal of Fluid Mechanics 234: 171-190.
[9] Pan Y, Suga K. (2005). Numerical simulation of binary liquid droplet collision. Physics of Fluids 17(8): 082105.
[10] Qiang HF, Shi C, Chen FZ, Han YW. (2013). Simulation of two-dimensional droplet collisions based on SPH method of multi-phase flows with large density differences. Acta Phys. Sin. 62(21): 245-259. https://doi.org/10.7498/aps.62.214701
[11] Liu ZJ, Zhang C, Wu LL, Wu JJ. (2015). Numerical simulation of head-on binary collision of droplets in gas phase environment. Chinese Journal of Computational Mechanics 32(1): 136-141.
[12] Yin J, Kong W, Wang FX, Liu H, Yang K. (2017). Experimental investigation of binary supercooled water droplet collision. Journal of Shanghai Jiao Tong University 51(8): 939-945.
[13] Hirt CW, Nichols BD. (1981). Volume of fluid (VOF) method for the dynamics of free boundaries. Journal of Computational Physics 39(1): 201–225.
[14] Wang J, Li QH, Lu M. (2003). Numerical method for free-surface fluid flow-a review. Chinese Journal of Computational Mechanics 2(1): 101-108.
[15] Brackbill JU, Kothe DB, Zemach C. (1992). A continuum method for modeling surface tension. Academic Press Professional, Inc. 100(2): 335-354. https://doi.org/10.1016/0021-9991(92)90240-Y
[16] Zheng X. (2018). Numerical simulation of aseismatic reinforced concrete frame structure with fiber reinforced plastics. Chemical Engineering Transactions 66: 1141-1146. https://doi.org/10.3303/CET1866191
[17] Isdale JD, Morris R. (1972). Physical properties of sea water solutions: density. Desalination 10(4): 329-339.
[18] Isdale JD, Spence CM, Tudhope JS. (1972). Physical properties of sea water solutions: viscosity. Desalination 10(4): 319-328.
[19] Qi XN. (2008) Research on the shower cooling tower. Shanghai Jiao Tong University.
[20] Chen S. (2018). Numerical simulation of split-hopkinson pressure bar test on high-density polyethylene. Chemical Engineering Transactions 66: 271-276 https://doi.org/10.3303/CET1866046
[21] Xia SY, Hu CB. (2014). Direct numerical simulation of head-on binary collision of aluminum oxide droplet. Applied Mathematics and Mechanics 35(04): 377-388.