K. Aboubi, L. Robillard, E. Bilgen and P. Vasseur
The present study deals with two‐dimensional convective motion due tothe effect of a centrifugal force field on a fluid contained between twohorizontal concentric cylinders, for…
Abstract
The present study deals with two‐dimensional convective motion due to the effect of a centrifugal force field on a fluid contained between two horizontal concentric cylinders, for the particular case of an adiabatic inner boundary (zero heat flux) and a constant heat flux imposed on the outer boundary. The normal terrestrial gravity is considered negligible. Governing equations for a two‐dimensional flow field are solved using analytical and numerical techniques. Based on a concentric flow approximation, the analytical solution is obtained in terms of the Rayleigh number and the radius ratio. The numerical solution is based on a finite difference method. Results indicate that the flow field always consists of two symmetrical cells at incipient convection even at radius ratios near unity. A good agreement is found between the analytical and numerical solutions at finite amplitude convection.
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K. Aboubi, L. Robillard and P. Vasseur
The natural two‐dimensional convection taking place between horizontal concentric cylinders filled with a satured anisotropic porous medium is studied numerically. The anisotropy…
Abstract
The natural two‐dimensional convection taking place between horizontal concentric cylinders filled with a satured anisotropic porous medium is studied numerically. The anisotropy concerns exclusively the permeability. Isothermal boundary conditions are applied on both inner and outer boundaries, with the outer boundary being warmer. The effects of the anisotropic permeability ratio K*, of the orientation angle of the principal axes defined by γ, and of the Rayleigh number Ra* on the flow and heat transfer are investigated. Results indicate that a net circulating flow around the annulus is generated, except for values of γ that preserve the symmetry of flow conditions with respect to the vertical diameter. It is also shown that the anisotropic part of the resistivity tensor is equivalent to a magnetic resistivity tensor.
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Alejandro Clausse, Nicolás Silin and Gustavo Boroni
The purpose of this paper is to obtain a permeability law of a gas flow through a permeable medium using particle image velocimetry experimental data as primal information, which…
Abstract
Purpose
The purpose of this paper is to obtain a permeability law of a gas flow through a permeable medium using particle image velocimetry experimental data as primal information, which is conflated with numerical calculations by means of a multi-scale method.
Design/methodology/approach
The D2Q9 single-relaxation-time Lattice Boltzmann model (LBM) implemented in GPU is used for the numerical calculations. In a first homogenized micro-scale, the drag forces are emulated by means of an effective Darcy law acting only in the close neighborhood of the solid structures. A second mesoscopic level of homogenization makes use of the effective drag forces resulting from the first-scale model.
Findings
The procedure is applied to an experiment consisting of a regular array of wires. For the first level of homogenization, an effective drag law of the individual elemental obstacles is produced by conflating particle image velocimetry measurements of the flow field around the wires and numerical calculations performed with a GPU implementation of the LBM. In the second homogenization, a Darcy–Forchheimer correlation is produced, which is used in a final homogenized LBM model.
Research limitations/implications
The numerical simulations at the first level of homogenization require a substantial amount of calculations, which in the present case were performed by means of the computational power of a GPU.
Originality/value
The homogenization procedure can be extended to other permeable structures. The micro-scale-level model retrieves the fluid-structure forces between the flow and the obstacles, which are difficult to obtain experimentally either from direct measurement or by indirect assessment from velocity measurements.
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Qian Li, Weihua Cai, Xiaojing Tang, Yicheng Chen, Bingxi Li and Ching-Yao Chen
The aim of this study is to numerically simulate the density-driven convection in heterogeneous porous media associated with anisotropic permeability field, which is important to…
Abstract
Purpose
The aim of this study is to numerically simulate the density-driven convection in heterogeneous porous media associated with anisotropic permeability field, which is important to the safe and stable long term CO2 storage in laminar saline aquifers.
Design/methodology/approach
The study uses compact finite difference and the pseudospectral method to solve Darcy’s law.
Findings
The presence of heterogeneous anisotropy may result in non-monotonic trend of the breakthrough time and quantity of CO2 dissolved in the porous medium, which are important to the CO2 underground storage.
Originality/value
The manuscript numerically study the convective phenomena of mixture contained CO2 and brine. The phenomena are important to the process of CO2 enhanced oil recovery. Interesting qualitative patterns and quantitative trends are revealed in the manuscript.
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Mourad Moderres, Said Abboudi, Malika Ihdene, Sofiane Aberkane and Abderahmane Ghezal
Double-diffusive convection within a tri-dimensional in a horizontal annulus partially filled with a fluid-saturated porous medium is numerically investigated. The aim of this…
Abstract
Purpose
Double-diffusive convection within a tri-dimensional in a horizontal annulus partially filled with a fluid-saturated porous medium is numerically investigated. The aim of this work is to understand the effects of a source of heat and solute on the fluid flow and heat and mass transfer rates.
Design/methodology/approach
In the formulation of the problem, the Darcy–Brinkman–Forchheimer model is adopted to the fluid flow in the porous annulus. The laminar flow regime is considered under steady state conditions. Moreover, the transport equation for continuity, momentum, energy and mass transfer are solved using the Patankar–Spalding technique.
Findings
Through this investigation, the predicted results for both average Nusselt and Sherwood numbers were correlated in terms of Lewis number, thermal Grashof number and buoyancy ration. A comparison was made with the published results and a good agreement was found.
Originality/value
The paper’s results are validated by favorable comparisons with previously published results. The results of the problem are presented in graphical forms and discussed. This paper aims to study the behavior of the flow structure and heat transfer and mass for different parameters.