The Experts below are selected from a list of 19998 Experts worldwide ranked by ideXlab platform
Patrice Bacchin - One of the best experts on this subject based on the ideXlab platform.
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Membranes: A Variety of Energy Landscapes for Many Transfer Opportunities
Membranes, 2018Co-Authors: Patrice BacchinAbstract:A membrane can be represented by an energy landscape that solutes or colloids must cross. A model accounting for the momentum and the mass balances in the membrane energy landscape establishes a new way of writing for the Darcy Law. The counter-pressure in the Darcy Law is no longer written as the result of an osmotic pressure difference but rather as a function of colloid-membrane interactions. The ability of the model to describe the physics of the filtration is discussed in detail. This model is solved in a simplified energy landscape to derive analytical relationships that describe the selectivity and the counter-pressure from ab initio operating conditions. The model shows that the stiffness of the energy landscape has an impact on the process efficiency: a gradual increase in interactions (such as with hourglass pore shape) can reduce the separation energetic cost. It allows the introduction of a new paradigm to increase membrane efficiency: the accumulation that is inherent to the separation must be distributed across the membrane. Asymmetric interactions thus lead to direction-dependent transfer properties and the membrane exhibits diode behavior. These new transfer opportunities are discussed.
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Membranes: A Variety of Energy Landscapes for Many Transfer Opportunities
Membranes, 2018Co-Authors: Patrice BacchinAbstract:A membrane can be represented by an energy landscape that solutes or colloids must cross. A model accounting for the momentum and the mass balances on the membrane energy landscape establishes a new way of writing for the Darcy Law. The counter pressure in the Darcy Law is no longer written as the result of an osmotic pressure difference but rather as a function of colloid-membrane interactions. The ability of the model to describe the physics of the filtration is discussed in detail. This model is solved on a simplified energy landscape to derive analytical relationships that describe the selectivity and the counter pressure from ab-initio operating conditions. The model shows that the stiffness of the energy landscape has an impact on the process efficiency: a gradual increase in interactions (like with hourglass pore shape) can reduce the separation energetic cost. It allows the introduction of a new paradigm to increase membrane efficiency: the accumulation that is inherent to the separation must be distributed across the membrane. Asymmetric interactions thus lead to direction-dependent transfer properties and the membrane exhibits diode behavior. These new transfer opportunities are discussed.
M. Sheikholeslami - One of the best experts on this subject based on the ideXlab platform.
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numerical approach for mhd al2o3 water nanofluid transportation inside a permeable medium using innovative computer method
Computer Methods in Applied Mechanics and Engineering, 2019Co-Authors: M. SheikholeslamiAbstract:Abstract Innovative numerical approach was employed to demonstrate nanofluid MHD flow through a porous enclosure. To model porous medium, Darcy Law has been employed. Radiation impact was included in energy equation. The new method (CVFEM) has been employed due to complex shape of porous cavity. Aluminium oxide with different shapes was dispersed in to water. Viscosity of nanofluid changes with Brownian motion impacts. Roles of radiation, buoyancy and Hartmann number on treatment of alumina were displayed. Results prove that convection detracts with augment of magnetic forces. Radiation can reduce the temperature gradient.
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numerical modeling for alumina nanofluid magnetohydrodynamic convective heat transfer in a permeable medium using Darcy Law
International Journal of Heat and Mass Transfer, 2018Co-Authors: M. Sheikholeslami, S A Shehzad, Ahmad ShafeeAbstract:Abstract CVFEM is employed in this article to model alumina nanofluid magnetohydrodynamic flow through a permeable enclosure. Influences of Hartmann number, buoyancy, radiation parameters on nanofluid treatment were displayed. Viscosity and thermal conductivity of alumina are predicted considering Brownian motion and shape factor impacts. Results are displayed that Lorentz forces boosts the conduction mechanism. Nu ave enhances with reduce of Ha . Augmenting radiation parameter makes thermal boundary layer to be thinner.
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transportation of mhd nanofluid free convection in a porous semi annulus using numerical approach
Chemical Physics Letters, 2017Co-Authors: M. Sheikholeslami, D D GanjiAbstract:Abstract Nanofluid free convection in presence of Lorentz forces in a permeable semi annulus is simulated using Control Volume based Finite Element Method. Impact of porous media on governing equations is considered by means of Darcy Law. Brownian motion impact on properties of nanofluid is taken into account using Koo-Kleinstreuer-Li (KKL) model. Important parameters are inclination angle ( ξ ) , CuO-water volume fraction ( ϕ ) , Hartmann ( Ha ) and Rayleigh ( Ra ) numbers for porous medium. A formula for Nuave is provided. Results indicated that temperature gradient detracts with enhance of Ha but it enhances with rise of ξ , Ra . Heat transfer augmentation enhances with rise of Lorentz forces.
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cuo water nanofluid free convection in a porous cavity considering Darcy Law
European Physical Journal Plus, 2017Co-Authors: M. SheikholeslamiAbstract:The natural convection of a CuO-water nanofluid in a permeable cavity is simulated using the Darcy Law. The Brownian motion impact on the properties of the nanofluid is taken into account using the KKL model. The effect of Lorentz forces on the nanofluid hydrothermal behavior are considered. The control volume based finite element method is applied to solve the final equations. Roles of CuO-water volume fraction (\(\phi\)), Rayleigh (Ra) and Hartmann (Ha) numbers for a porous medium are reported. Results show that the Nusselt number decreases with increasing Ha but it increases with increasing \(\phi\), Ra.
Mohsen Sheikholeslami - One of the best experts on this subject based on the ideXlab platform.
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Magnetohydrodynamic nanofluid radiative thermal behavior by means of Darcy Law inside a porous media
Scientific Reports, 2019Co-Authors: Trung Nguyen-thoi, Poom Kumam, Zahir Shah, Mohsen Sheikholeslami, Ahmad ShafeeAbstract:Radiative nanomaterial thermal behavior within a permeable closed zone with elliptic hot source is simulated. Darcy Law is selected for simulating permeable media in existence of magnetic forces. Contour plots for various buoyancy, Hartmann numbers and radiation parameter were illustrated. Carrier fluid is Al2O3-water with different shapes. Outputs prove that conduction mode augments with enhance of Ha. Nu augments with considering radiation source term.
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Application of Darcy Law for nanofluid flow in a porous cavity under the impact of Lorentz forces
Journal of Molecular Liquids, 2018Co-Authors: Mohsen SheikholeslamiAbstract:Abstract In order to simulate nanofluid MHD transportation in a permeable cavity, Darcy Law is utilized. Impacts of radiation parameter, buoyancy and Lorentz forces on nanofluid characteristics have been depicted via CVFEM. Al2O3-water nanofluid is selected considering shape factor and Brownian motion impacts on its properties. Results reveal that conduction mode improves with rise of magnetic forces. So, thermal boundary layer becomes thinner with increase of magnetic forces.
Nicola Zamponi - One of the best experts on this subject based on the ideXlab platform.
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existence of weak solutions to a continuity equation with space time nonlocal Darcy Law
Communications in Partial Differential Equations, 2020Co-Authors: Luis A Caffarelli, Maria Pia Gualdani, Nicola ZamponiAbstract:In this manuscript, we consider a non-local porous medium equation with non-local diffusion effects given by a fractional heat operator { ∂ t u = div ( u ∇ p ) , ∂ t p = − ( − Δ ) s p + u β , in tw...
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existence of weak solutions to a continuity equation with space time nonlocal Darcy Law
arXiv: Analysis of PDEs, 2018Co-Authors: Luis A Caffarelli, Maria Pia Gualdani, Nicola ZamponiAbstract:In this manuscript we consider a porous medium equation with non-local diffusion effects given by a fractional heat operator $\partial_t + (-\Delta)^s$ in two space dimensions. Global in time existence of weak solutions is shown by employing a time semi-discretization of the equations, an energy inequality, a higher order integral estimate, and a generalized version of the Div-Curl lemma.
F Duval - One of the best experts on this subject based on the ideXlab platform.
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A Darcy Law for the drift velocity in a two-phase flow model
Journal of Computational Physics, 2007Co-Authors: Herve Guillard, F DuvalAbstract:This work deals with the design and numerical approximation of an Eulerian mixture model for the simulation of two-phase dispersed flows. In contrast to the more classical two-fluid or Drift-flux models, the influence of the velocity disequilibrium is taken into account through dissipative second-order terms characterized by a Darcy Law for the relative velocity. As a result, the convective part of the model is always unconditionally hyperbolic. We show that this model corresponds to the first-order equilibrium approximation of classical two-fluid models. A finite volume approximation of this system taking advantage of the hyperbolic nature of the convective part of the model and of the particular structural form of the dissipative part is proposed. Numerical applications are presented to assess the capabilities of the model. © 2007 Elsevier Inc. All rights reserved.
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a Darcy Law for the drift velocity in a two phase flow model
Journal of Computational Physics, 2007Co-Authors: Herve Guillard, F DuvalAbstract:This work deals with the design and numerical approximation of an Eulerian mixture model for the simulation of two-phase dispersed flows. In contrast to the more classical two-fluid or Drift-flux models, the influence of the velocity disequilibrium is taken into account through dissipative second-order terms characterized by a Darcy Law for the relative velocity. As a result, the convective part of the model is always unconditionally hyperbolic. We show that this model corresponds to the first-order equilibrium approximation of classical two-fluid models. A finite volume approximation of this system taking advantage of the hyperbolic nature of the convective part of the model and of the particular structural form of the dissipative part is proposed. Numerical applications are presented to assess the capabilities of the model.
