Convective Instability in Forchheimer-Prats Configuration with a Saturating Power-Law Fluid

Document Type : Research Paper

Authors

Energy Laboratory, Physics Department, Faculty of Sciences, Abdelmalek Essaadi University, Tétouan, 99350, Morocco

Abstract

The paper deals with the combined effect of non-Newtonian saturating fluid and horizontal flow rate on the thermal convection in a highly permeable, porous plane layer saturated with a power-law model. Asymmetric boundary conditions are assumed, with a cooled free surface at the top and a heated, impermeable, rigid wall at the bottom. The generalised Forchheimer equation is employed to model the power-law fluid movement. Convection cells emerge in the power-law fluid because of vertical temperature gradient imposed by the thermal boundaries. The onset of this scenario can be studied using linear stability theory, which leads to an eigenvalue problem. The latter is solved either numerically, employing shooting schemes, or analytically, using one-order Galerkin approach. The present study is considered an extension of the classical Prats problem. When the Peclet number, which defines the flow rate, is negligible, the configuration switches to the special case of Darcy-Rayielgh instability. The results show that the form drag exhibits a stronger stabilizing influence in shear-thinning fluids compared to shear-thickening and Newtonian ones since the saturating fluid is described by the power-law model. This scenario appears in the specific range of the Peclet number. In general, this investigation can be used to understand the heat transfer process in subsurface hydrocarbon reservoirs where the fluid may exhibit non-Newtonian behaviour.

Keywords

Main Subjects

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[1] Combarnous, M.A., Bories, S.A., Hydrothermal Convection in Saturated Porous Media, Advances in Hydroscience, 10, 1975, 231-307.
[2] Nield, D.A., Bejan, A., Convection in Porous Media, Springer International Publishing AG, Cham, Switzerland, 2017.
[3] Vafai, K., Handbook of Porous Media, CRC Press, Taylor & Francis Group, Boca Raton, 2015
[4] Barletta, A., Route to absolute instability in porous media, Springer Nature, Cham, Switzerland, 2019.
[5] Gérard, A., Genter, A., Kohl, T., Lutz, P., Rose, P., Rummel, F., The deep EGS (Enhanced Geothermal System) project at Soultz-sous-Forêts (Alsace, France), Geothermics, 35(5), 2006, 473–483.
[6] Nie, R.S., Meng, Y.F., Jia, Y.L., Zhang, F.X., Yang, X.T., Niu, X.N., Dual porosity and dual permeability modeling of horizontal well in naturally fractured reservoir, Transport in Porous Media, 92(1), 2012, 213–235.
[7] Nield, D.A., Joseph, D.D., Effects of quadratic drag on convection in a saturated porous medium, Physics of Fluids, 28, 1985, 995–997
[8] He, X.S., Georgiadis, J.G., Natural convection in porous media: effect of weak dispersion on bifurcation, Journal of Fluid Mechanics, 216, 1990, 85-298
[9] Shivakumara, I.S., Sureshkumar, S., Convective instabilities in a viscoelastic-fluid-saturated porous medium with throughflow, Journal of Geophysics and Engineering, 4(1), 2007, 104–115.
[10] Barletta, A., Rees, D.A.S., On the onset of convection in a highly permeable vertical porous layer with open boundaries, Physics of Fluids, 31, 2019, 074106.
[11] Barletta, A., Celli, M., Rees, D.A.S., Darcy-Forchheimer flow with viscous dissipation in a horizontal porous layer: onset of convective instabilities, Journal of Heat Transfer, 131(7), 2009, 072602
[12] Chhabra, R.P., Richardson, J.F., Non–Newtonian flow and applied rheology: Non- Newtonian Flow and Applied Rheology, Elsevier, Oxford, 2008.
[13] Shenoy, A., Heat transfer to non-Newtonian fluids: fundamentals and analytical expressions, Wiley-VCH, Germany, 2018.
[14] Christopher, R.H., Middleman, S., Power-Law Flow through a Packed Tube, Industrial & Engineering Chemistry Fundamentals, 4(4), 1965, 422–426.
[15] Nield, D.A., A Further Note on the Onset of Convection in a Layer of a Porous Medium Saturated by a Non-Newtonian Fluid of Power-Law Type, Transport in Porous Media, 88(2), 2011, 187–191.
[16] Barletta, A., Storesletten, L., Linear instability of the vertical throughflow in a horizontal porous layer saturated by a power-law fluid, International Journal of Heat and Mass Transfer, 99, 2016, 293–302.
[17] Celli, M., Barletta, A., Onset of convection in a non-Newtonian viscous flow through a horizontal porous channel, International Journal of Heat and Mass Transfer, 117, 2018, 1322–1330.
[18] Brandão, P.V., Celli, M., Barletta, A., Alves, L.S.D.B., Convection in a Horizontal Porous Layer with Vertical Pressure Gradient Saturated by a Power-Law Fluid, Transport in Porous Media, 130(2), 2019, 613–625.
[19] Federico, V.D., Pinelli, M., Ugarelli, R., Estimates of effective permeability for non-Newtonian fluid flow in randomly heterogeneous porous media, Stochastic Environmental Research and Risk Assessment, 24(7), 2010, 1067–1076.
[20] Celli, M., Impiombato, A.N., Barletta, A., Buoyancy-driven convection in a horizontal porous layer saturated by a power-law fluid: The effect of an open boundary, International Journal of Thermal Sciences,152, 2020, 106302.
[21] Finalyson, B.A., The Method of Weighted Residuals and Variational Principles, Society for Industrial and Applied Mathematics, 2013.
[22] Horton, C.W., Rogers, F.T., Convection Currents in a Porous Medium, Journal of Applied Physics, 16(2), 1945, 367–370.
[23] Lapwood, E.R., Convection of a fluid in a porous medium, Mathematical Proceedings of the Cambridge Philosophical Society, 44(4), 1948, 508–521.
[24] Prats, M., The effect of horizontal fluid flow on thermally induced convection currents in porous mediums, Journal of Geophysical Research, 71(20), 1966, 4835–4838.
[25] Nield, D.A., Onset of Thermohaline Convection in a Porous Medium, AGU Water Resources Research, 4(3), 1968, 553-560.
[26] Wilkes, K.E., Onset of Natural Convection in a Horizontal Porous Medium with Mixed Thermal Boundary Conditions, Journal of Heat Transfer, 117(2), 1995, 543-547.