Numerical solution to the multi- layer core- annular flow of two fluids with different viscosities using Spectral Element Method

Authors

1 Department of Mechanical Engineering, Yazd University, Yazd, Iran

2 Department of Mechanical Engineering, University of Tehran, Tehran, Iran

3 Engineering Department, Persian Gulf University, Bushehr, Iran

Abstract

The aim of this article is to develop a high order splitting scheme for the simulation of multi- layer core- annular flow of two fluids with different viscosities inside the two-dimensional channel. For this simulation, the incompressible fluids flow equations (Navier- Stokes) and concentration (volume fraction) equation are solved. The two-phase flow is modeled by the volume of fluid technique and with harmonic interpolation. The spectral element method is used for the spatial discretization and Adams- Bashforth method is adopted for the time integration. Velocity correction scheme is developed here as a high order splitting scheme for the coupling issue. To validate the numerical results they are compared with the analytic solution of fully developed flow. This comparison includes outflow velocity profile and pressure gradient. Also, the accuracy of numerical method has been investigated spatially and temporally. The form of core- annular flow has been investigated for various parameters and the results have been compared with experimental and other numerical works. Investigations show that the Reynolds number and core inlet thickness are two important parameters on the pattern of core- annular flow.

Keywords

Main Subjects


[1] Martínez-Palou R, Mosqueira M, Zapata B (2011) Transportation of heavy and extra-heavy crude oil by pipeline: A review. J Petrol Sci Eng 75(4): 274-282.
[2] Ooms G, Segal A, Van A (1983) A theoretical model for core-annular flow of a very viscous oil core and a water annulus through a horizontal pipe. Int J Multiphas Flow 10(1): 41-60.
[3] Bai R, Kelkar K,  Joseph D (1996) Direct Simulation of Interfacial Waves in a High Viscosity Ratio and Axisymmetric Core Annular Flow. J Fluid Mech 32: 1-34.
[4] Ghosh S, Das G, Das P (2010) Simulation of core annular downflow through CFD—A comprehensive study. Chem Eng Process 49(11): 122-128.
[5] Kaushik V, Ghosh S, Das G, Das P (2012) CFD simulation of core annular flow through sudden contraction and expansion. J Petrol Sci Eng 86(Supplement C): 153-164.
[6] Shi J, Gourma M, Yeung H (2017) CFD simulation of horizontal oil-water flow with matched density and medium viscosity ratio in different flow regimes. J Petrol Sci Eng 151(Supplement C): 373-383.
[7] d’Olce M, Martin J, Salin D, Talon L (2008) Pearl and mushroom instability patterns in two miscible fluids core annular flows. Phys Fluids 20(2): 14-24.
[8] Hormozi S, Burchard K, Frigaard I (2011) Multi-layer channel flows with yield stress fluids. J Non-Newton Fluid 166(5-6): 262-278.
[9] Patera A (1984) A spectral element method for fluid dynamics: Laminar flow in a channel expansion. J Comput Phys 54(3): 468-488.
[10] Karniadakis G, Sherwin S (1999) Spectral/hp Element Methods for CFD. Oxford University Press, New York.
[11] Fiétier N, Deville M (2003) Time-dependent algorithms for the simulation of viscoelastic flows with spectral element methods: applications and stability. J Comput Phys 186(1): 93-121.
[12] Jafari A, Fiétier N, Deville M (2010) A new extended matrix logarithm formulation for the simulation of viscoelastic fluids by spectral elements. Comput Fluids 39(9): 1425-1438.
[13] Karniadakis G, Israeli M, Orszag S (1991) High-order splitting methods for the incompressible Navier-Stokes equations. J Comput Phys 97(2): 414-443.
[14] Pourmoayed, A, Rahmati R, Gholami M (2018) A New Model for Two-Phase Flow in a Solar Still Improved by a Porous Layer. Journal of Solid and Fluid Mechanics 8(1): 171-182.
[15] Patankar S, (1980) Numerical Heat Transfer and Fluid Flow. Hemisphere Publishing Corporation.
[16] Le Bars M, Davaille A (2002) Stability of thermal convection in two superimposed miscible viscous fluids. J Fluid Mech 471: 339-363
[17] Bolis A (2013) Fourier Spectral/hp Element Method: Investigation of Time-Stepping and Parallelisation Strategies. PhD Thesis, in Department of Aeronautics. Imperial College London.
[18] Gear C, (1971) Numerical Initial Value Problems in Ordinary Differential Equations. Prentice Hall PTR.
[19] Cantwell C, Moxey D, Bolis A, Sherwin S (2015) Nektar++: An open-source spectral/ element framework. Comput Phys Commun 192: 205-219.