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Spin-affected reflexive and stretching separation of off-center droplet collision

Chengming He (何成明)1, Lianjie Yue (岳连捷)1,2, and Peng Zhang (张鹏)3,*

  • 1Wide Range Flight Engineering Science and Application Center, Institute of Mechanics, Chinese Academy of Sciences, No. 15 Beisihuanxi Road, Beijing 100190 China
  • 2State Key Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, Chinese Academy of Sciences, No. 15 Beisihuanxi Road, Beijing 100190 China
  • 3Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong Kong

  • *pengzhang.zhang@polyu.edu.hk
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Phys. Rev. Fluids 7, 013603 – Published 18 January, 2022

DOI: https://doi.org/10.1103/PhysRevFluids.7.013603

Abstract

Recent studies have demonstrated the significant roles of droplet self-spin motion in affecting the head-on collision of binary droplets. In this paper, we present a computational study by using the volume-of-fluid method to investigate the spin-affected droplet separation of off-center collisions, which are more probable in reality and phenomenologically richer than head-on collisions. Different separation modes are identified through a parametric study with varying spinning speed and impact parameter. A prominent finding is that increasing the droplet spinning speed tends to suppress the reflexive separation and to promote the stretching separation. Physically, the reflexive separation is suppressed because the increased rotational energy reduces the excessive reflexive kinetic energy within the droplet, which is the cause for the droplet reflexive separation. The stretching separation is promoted because the increased droplet angular momentum enhances the local stretching flow within the droplet, which tends to separate the droplet. The roles of orbital angular momentum and spin angular momentum in affecting the droplet separation are further substantiated by studying the collision between two spinning droplets with either the same or opposite chirality. In addition, a theoretical model based on conservation laws is proposed to qualitatively describe the boundaries of coalescence-separation transition influenced by droplet self-spin motion.

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References (48)

  1. P. R. Brazier-Smith, S. G. Jennings, and J. Latham, The interaction of falling water drops: Coalescence, Proc. R. Soc. London, Ser. A 326, 393 (1972).
  2. S. G. Bradley and C. D. Stow, Collisions between liquid drops, Proc. R. Soc. A 287, 635 (1978).
  3. N. Ashgriz and J. Y. Poo, Coalescence and separation in binary collisions of liquid drops, J. Fluid Mech. 221, 183 (1990).
  4. Y. J. Jiang, A. Umemura, and C. K. Law, An experimental investigation on the collision behaviour of hydrocarbon droplets, J. Fluid Mech. 234, 171 (1992).
  5. J. Qian and C. K. Law, Regimes of coalescence and separation in droplet collision, J. Fluid Mech. 331, 59 (1997).
  6. J.-P. Estrade, H. Carentz, G. Lavergne, and Y. Biscos, Experimental investigation of dynamic binary collision of ethanol droplets–a model for droplet coalescence and bouncing, Int. J. Heat Fluid Flow 20, 486 (1999).
  7. G. Brenn and V. Kolobaric, Satellite droplet formation by unstable binary drop collisions, Phys. Fluids 18, 087101 (2006).
  8. C. Gotaas, P. Havelka, H. A. Jakobsen, H. F. Svendsen, M. Hase, N. Roth, and B. Weigand, Effect of viscosity on droplet-droplet collision outcome: Experimental study and numerical comparison, Phys. Fluids 19, 102106 (2007).
  9. K.-L. Pan, P.-C. Chou, and Y.-J. Tseng, Binary droplet collision at high Weber number, Phys. Rev. E 80, 036301 (2009).
  10. C. Rabe, J. Malet, and F. Feuillebois, Experimental investigation of water droplet binary collisions and description of outcomes with a symmetric Weber number, Phys. Fluids 22, 047101 (2010).
  11. C. Tang, P. Zhang, and C. K. Law, Bouncing, coalescence, and separation in head-on collision of unequal-size droplets, Phys. Fluids 24, 022101 (2012).
  12. M. Sommerfeld and M. Kuschel, Modelling droplet collision outcomes for different substances and viscosities, Exp. Fluids 57, 187 (2016).
  13. G. Finotello, R. F. Kooiman, J. T. Padding, K. A. Buist, A. Jongsma, F. Innings, and J. Kuipers, The dynamics of milk droplet–droplet collisions, Exp. Fluids 59, 17 (2018).
  14. K. H. Al-Dirawi and A. E. Bayly, A new model for the bouncing regime boundary in binary droplet collisions, Phys. Fluids 31, 027105 (2019).
  15. G. Brenn, Droplet collision, in Handbook of Atomization and Sprays, edited by N. Ashgriz (Springer, Berlin, 2011), p. 157–181.
  16. M. Orme, Experiments on droplet collisions, bounce, coalescence and disruption, Prog. Energy Combust. Sci. 23, 65 (1997).
  17. N. Roth, C. Rabe, B. Weigand, F. Feuillebois, and J. Malet, Droplet collision outcomes at high Weber number, in Proceedings of the 21st Conference on Liquid Atomization and Spray Systems (ILASS, Mugla, Turkey, 2007).
  18. L. Reitter, M. Liu, J. Breitenbach, K.-L. Huang, D. Bothe, G. Brenn, K.-L. Pan, I. Roisman, and C. Tropea, Experimental and computational investigation of binary drop collisions under elevated pressure, in Proceedings of ILASS Europe. 28th European Conference on Liquid Atomization and Spray Systems (ILASS, Valencia, Spain, 2017).
  19. K. Krishnan and E. Loth, Effects of gas and droplet characteristics on drop-drop collision outcome regimes, Int. J. Multiphase Flow 77, 171 (2015).
  20. F. Blanchette, L. Messio, and J. W. M. Bush, The influence of surface tension gradients on drop coalescence, Phys. Fluids 21, 072107 (2009).
  21. K. Sun, P. Zhang, Z. Che, and T. Wang, Marangoni-flow-induced partial coalescence of a droplet on a liquid/air interface, Phys. Rev. Fluids 3, 023602 (2018).
  22. F. Jia, K. Sun, P. Zhang, C. Yin, and T. Wang, Marangoni effect on the impact of droplets onto a liquid-gas interface, Phys. Rev. Fluids 5, 073605 (2020).
  23. K. Sun, F. Jia, P. Zhang, L. Shu, and T. Wang, Marangoni Effect in Bipropellant Droplet Mixing during Hypergolic Ignition, Phys. Rev. Appl. 15, 034076 (2021).
  24. G. Finotello, J. T. Padding, N. G. Deen, A. Jongsma, F. Innings, and J. Kuipers, Effect of viscosity on droplet-droplet collisional interaction, Phys. Fluids 29, 067102 (2017).
  25. A. Moreira, A. Moita, and M. Panao, Advances and challenges in explaining fuel spray impingement: How much of single droplet impact research is useful?, Prog. Energy Combust. Sci. 36, 554 (2010).
  26. R. Kamali and M. Mofarrahi, Numerical investigation of various spray breakup and droplet collision models in the modeling of in-cylinder fuel spray, Atomization Sprays 22, 843 (2012).
  27. M. Sommerfeld and L. Pasternak, Advances in modelling of binary droplet collision outcomes in sprays: A review of available knowledge, Int. J. Multiphase Flow 117, 182 (2019).
  28. K.-L. Pan, K.-L. Huang, W.-T. Hsieh, and C.-R. Lu, Rotational separation after temporary coalescence in binary droplet collisions, Phys. Rev. Fluids 4, 123602 (2019).
  29. X. Chen and V. Yang, Thickness-based adaptive mesh refinement methods for multi-phase flow simulations with thin regions, J. Comput. Phys. 269, 22 (2014).
  30. C. He, X. Xia, and P. Zhang, Non-monotonic viscous dissipation of bouncing droplets undergoing off-center collision, Phys. Fluids 31, 052004 (2019).
  31. C. He, X. Xia, and P. Zhang, Vortex-dynamical implications of nonmonotonic viscous dissipation of off-center droplet bouncing, Phys. Fluids 32, 032004 (2020).
  32. C. He and P. Zhang, Nonaxisymmetric flow characteristics in head-on collision of spinning droplets, Phys. Rev. Fluids 5, 113601 (2020).
  33. S. Popinet, An accurate adaptive solver for surface-tension-driven interfacial flows, J. Comput. Phys. 228, 5838 (2009).
  34. S. Popinet, Numerical models of surface tension, Annu. Rev. Fluid Mech. 50, 49 (2018).
  35. X. Chen, D. Ma, and V. Yang, Collision outcome and mass transfer of unequal-sized droplet collision, in Proceedings of the 50th AIAA Aerospace Sciences Meeting (AIAA, Reston, VA, 2012).
  36. X. Chen, D. Ma, V. Yang, and S. Popinet, High-fidelity simulations of impinging jet atomization, Atomization Sprays 23, 1079 (2013).
  37. C. Hu, S. Xia, C. Li, and G. Wu, Three-dimensional numerical investigation and modeling of binary alumina droplet collisions, Int. J. Heat Mass Transfer 113, 569 (2017).
  38. C. Tang, J. Zhao, P. Zhang, C. K. Law, and Z. Huang, Dynamics of internal jets in the merging of two droplets of unequal sizes, J. Fluid Mech. 795, 671 (2016).
  39. X. Xia, C. He, D. Yu, J. Zhao, and P. Zhang, Vortex-ring-induced internal mixing upon the coalescence of initially stationary droplets, Phys. Rev. Fluids 2, 113607 (2017).
  40. X. Xia, C. He, and P. Zhang, Universality in the viscous-to-inertial coalescence of liquid droplets, Proc. Natl Acad. Sci. USA 116, 23467 (2019).
  41. P. Zhang and C. K. Law, An analysis of head-on droplet collision with large deformation in gaseous medium, Phys. Fluids 23, 042102 (2011).
  42. X. Chen, D. Ma, P. Khare, and V. Yang, Energy and mass transfer during binary droplet collision, in Proceedings of the 49th AIAA Aerospace Sciences Meeting (AIAA, Reston, VA, 2011).
  43. S. Tanguy and A. Berlemont, Application of a level set method for simulation of droplet collisions, Int. J. Multiphase Flow 31, 1015 (2005).
  44. K. Sun, P. Zhang, M. Jia, and T. Wang, Collision-induced jet-like mixing for droplets of unequal-sizes, Int. J. Heat Mass Transfer 120, 218 (2018).
  45. C. He, L. Yue, and P. Zhang, A computational model for spinning effects on post-collision velocities of bouncing droplets, Atomization Sprays 31, 43 (2021).
  46. F. A. Williams, Combustion Theory, 2nd ed. (CRC Press, Boca Raton, FL, 2018).
  47. V. I. Arnol'd, Catastrophe Theory (Springer Science & Business Media, Berlin, 2003).
  48. K. H. Al-Dirawi, K. H. Al-Ghaithi, T. C. Sykes, J. R. Castrejón-Pita, and A. E. Bayly, Inertial stretching separation in binary droplet collisions, J. Fluid Mech. 927, A9 (2021).

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Phys. Rev. Fluids 7, 013603– Published 18 January, 2022
  • Received 11 September 2021
  • Accepted 20 December 2021
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