Analyses of Phase Change Separation Phenomenon in Flush Tank Using Volume of Fluid Method
Abstract
In this paper the simulation on flush tank is solved by Navier-Stokes equations with modified k - ε turbulence model with realizable RNG equation. The performance of the flushevaluated with the three-dimension flushing flow simulating method through the distribution of the two-phase flow field, the total flow pressure, the flow speed at the surface and the siphoning bent tube.Those parameters have provided a high efficiency approach to develop new water-saving flush tank for commercial application.The recirculation zone and bubble under various boundary conditions (including adiabatic and non-adiabatic boundary conditions) using numerical simulations have been studied. On analyzing the multiphase flow, it can be seen that while considering fluid alone, phase separation is more at the outlet than at the inlet of tank. In the run arm phase separation is negligible due to the effect of gravity. Under the same initial flow conditions, wake downstream of the wave is found to be much more turbulent than that of the circular one. In addition, as Re increased, the turbulence of the wake flow increased and its length downstream of the wave increased.
Full Text:
PDFReferences
Tung, K.W. and Parlange, J.Y.,. Note on the motion of long bubbles in closed tube influence of surface tension, ActaMechanica,1976, 24, 313–317.
Polonsky, S., Shemer, L., Barnea, D.,. Relation between the Taylor bubble motion and the velocity field ahead of it. Int. J. Multiphase Flow,1999, 25, 957–975.https://doi.org/10.1016/S0301-9322(99)00037-3
Tudose, E.T. and Kawaji, M.,. Experimental investigation of Taylor bubble acceleration mechanism in slug flow. Chem. Eng. Sci.,1999, 54, 5671–5775.https://doi.org/10.1016/S0009-2509(99)00149-9
Zukoski, E.E.,. Influence of viscosity, surface tension and inclination angle on motion of long bubbles in closed tubes. Journal of Fluid Mechanics,1966, 25, 821– 837.http://resolver.caltech.edu/CaltechAUTHORS:20110103-104138242
Lu, X., Prosperetti, A.,. Axial stability of Taylor bubbles. J. Fluid Mech., 2006, 568, 173-192.https://doi.org/10.1017/S0022112006002205
Rothman, D.H., Keller, J.M.,. Immiscible cellular automaton fluid. J. Stat. Phys., 1988, 52, 1119-1127.https://doi.org/10.1007/BF01019743
Shan, X., Chen, H.,. Lattice Boltzmann model for simulating flows with multiple phases and components, Phys. Rev. E,1993, 47, 1815–1819.https://doi.org/10.1103/PhysRevE.47.1815
He, X., Chen, S., Zhang R.,. A lattice Boltzmann scheme for incompressible multiphase flow and its application in simulation of Rayleigh–Taylor instability. J. Comput. Phys., 1999, 152, 642-663.https://doi.org/10.1006/jcph.1999.6257
Gingold R.A,Monaghan J.J.,. Smoothed particle hydrodynamics - Theory and application to non-spherical stars,Mon.Not.R.astr.Soc,1977, 181,375-389. https://doi.org/10.1093/mnras/181.3.375
Brochard F.,. Motions of droplets on solid surfaces induced by chemical or thermal gradients.Langmuir, 1989, 5, 432–438. https://doi.org/10.1021/la00086a025
Sharma A., Introduction to computational fluid dynamics: development, application and analysis, Wiley publications, USA, 2016.
White F. M., Fluid mechanics, Mc-Graw hill publications, USA, 2011.
Refbacks
- There are currently no refbacks.