Three-dimensional double-diffusive natural convection with opposing buoyancy effects in porous enclosure by Boundary Element Method

Kramer, J.; Ravnik, Jure; Jecl, R.; Škerget, L.

doi:10.2495/cmem-v1-n2-103-115

Cited by 3 publications

(3 citation statements)

References 24 publications

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“…The problem setting follows [21], and we reuse most of the parameters from the 2D computation, except for Ra = 1e4 and N = 1. The structured tetrahedral mesh discretizing the domain ⌦ = (0, 0.75) 3 consists of 295488 elements and 50653 vertices, and we employ a fixed timestep of t = 1E 3.…”

Section: Double-di↵usion In Porous Cavitiesmentioning

confidence: 99%

“…Notable examples are the density fingering of exothermic fronts in Hele-Shaw cells [18], where hydrodynamic instabilities are strongly influenced by the chemical reactions taking place at di↵erent spatial and temporal scales; convection-driven Turing patterns generated using Schnackenberg-Darcy models [25]; reversible reactive flow and viscous fingering in chromatographic separation [2,28]; plankton dynamics [24]; forced-convective heat and mass transfer in fibrous porous materials [7]; or the bioconvection in porous suspensions of oxytactic bacteria [16,22]. Phenomena of this kind are also relevant in so-called doubly-di↵usive flows [21,27,30], where convective e↵ects are driven by two di↵erent density gradients having diverse rates of di↵usion.…”

Section: Introductionmentioning

confidence: 99%

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Partitioned coupling of advection–diffusion–reaction systems and Brinkman flows

Lenarda

Paggi

Ruiz–Baier

2017

Journal of Computational Physics

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We present a partitioned algorithm aimed at extending the capabilities of existing solvers for the simulation of coupled advection-di↵usion-reaction systems and incompressible, viscous flow. The space discretization of the governing equations is based on mixed finite element methods defined on unstructured meshes, whereas the time integration hinges on an operator splitting strategy that exploits the di↵er-ences in scales between the reaction, advection, and di↵usion processes, considering the global system as a number of sequentially linked sets of partial di↵erential, and algebraic equations. The flow solver presents the advantage that all unknowns in the system (here vorticity, velocity, and pressure) can be fully decoupled and thus turn the overall scheme very attractive from the computational perspective. The robustness of the proposed method is illustrated with a series of numerical tests in 2D and 3D, relevant in the modelling of bacterial bioconvection and Boussinesq systems.

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Section: Double-di↵usion In Porous Cavitiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Partitioned coupling of advection–diffusion–reaction systems and Brinkman flows

Lenarda

Paggi

Ruiz–Baier

2017

Journal of Computational Physics

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“…Therefore the governing set of equations is transformed into a velocity-vorticity formulation. The numerical code was already used for several applications of pure fluid flow [12,13], as well as porous media applications [14,15]. Several numerical results are presented in order to analyze the influence of nanofluid in combination with porous media on heat transfer and fluid flow characteristics.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of convective flow in a non-darcy porous cavity filled with nanofluid

Stajnko¹,

Jecl²,

Ravnik³

2016

Int. J. CMEM

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Suspensions of nanoscale particles and fluids have been recently subject of intense research, since it was proved that they considerably improve heat transfer capabilities of the fluid which can be crucial in several technological processes. Several applications can be found in the field of porous media flow, such as oil recovery systems, thermal and geothermal energy, nuclear reactors cooling. Since nanofluids are a mixture of a solid and fluid phase, in general, the two phase mathematical model would be the most appropriate to use. However, due to very small size of nanoparticles (1-100 nm) can be assumed, that they behave as a water molecule and a single phase model along with empirical correlations for nanofluid properties can be used. In the present study a convective flow through porous cavity fully saturated with nanofluid is analyzed in detail using the single phase mathematical model based on the Navier-Stokes equations taking into account the non-Darcy parameters. The mathematical model is written at a macroscopic level enabling the simulation of the porous media flow. The solutions are obtained with the in house numerical code based on the Boundary Element Method, which was already proved to have some unique advantages when considering fluid flow problems in different configurations. The effects of the presence of different types of nanoparticles as well as the porous matrix were investigated in detail for different values of governing parameters in order to examine the improved heat transfer characteristics of added nanoparticles.

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Numerical Study of Convective Heat Transfer in an Inclined Porous Enclosure Saturated With Nanofluid

Stajnko

Jecl

Ravnik

2018

Advances in Fluid Mechanics XII

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The addition of nanoscale particles into the fluid is recently a common technology used in several industrial processes, since it has been proved that by introducing particles into the working fluid, the heat transfer characteristics can be improved crucially. However, the understanding of fundamental characteristics of nanofluid saturated porous media domains is still limited. The paper presents a numerical study of free convection in a porous enclosure saturated with a nanofluid. A single-phase mathematical model has been employed assuming that the suspension of nanoparticles in fluid can be modelled as a new fluid with effective properties. Fluid flow in porous media is modelled with the macroscopic Navier-Stokes equations, where the governing parameters are averaged over the representative elementary volume. The obtained set of partial differential equations is solved with use of the numerical code based on the Boundary Element Method, which was primarily developed for pure fluid flow applications and was already proved to be efficient for solving several problems of fluid mechanics. Numerical results for different values of governing parameters are obtained, focusing on the effect of different volume fractions of added nanoparticles and different inclination angles of the porous enclosure on the overall heat transfer through porous domain.

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Three-dimensional double-diffusive natural convection with opposing buoyancy effects in porous enclosure by Boundary Element Method

Cited by 3 publications

References 24 publications

Partitioned coupling of advection–diffusion–reaction systems and Brinkman flows

Partitioned coupling of advection–diffusion–reaction systems and Brinkman flows

Numerical simulation of convective flow in a non-darcy porous cavity filled with nanofluid

Numerical Study of Convective Heat Transfer in an Inclined Porous Enclosure Saturated With Nanofluid

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