Alexei Vjatkin^*, Svyatoslav Petukhov, Victor Kozlov

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2475-2488, 2024, DOI:10.32604/fdmp.2024.052377 - 28 October 2024

Abstract A genuine technological issue–the thermal convection of liquid in a rotating cavity–is investigated experimentally. The experiments are conducted within a horizontal annulus with isothermal boundaries. The inner boundary of the annulus has a higher temperature, thus exerting a stabilising influence on the system. It is shown that when the layer rotation velocity diminishes, two-dimensional azimuthally periodic convective rolls, rotating together with the cavity, emerge in a threshold manner. The development of convection is accompanied by a significant intensification of heat transfer through the layer. It is shown that the averaged thermal convection excitation in the… More > Graphic Abstract

Ivan Shubenkov^1,2,*, Tatyana Lyubimova^1,2, Evgeny Sadilov¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 1957-1970, 2024, DOI:10.32604/fdmp.2024.050167 - 23 August 2024

Abstract In this paper, we study the onset and development of three-dimensional convection in a tilted porous layer saturated with a liquid. The layer is subjected to a gravitational field and a strictly vertical temperature gradient. Typically, problems of thermal convection in tilted porous media saturated with a liquid are studied by assuming constant different temperatures at the boundaries of the layer, which prevent these systems from supporting conductive (non-convective) states. The boundary conditions considered in the present work allow a conductive state and are representative of typical geological applications. In an earlier work, we carried… More > Graphic Abstract

Igor B. Palymskiy^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 957-974, 2024, DOI:10.32604/fdmp.2024.048829 - 07 June 2024

Abstract The fully nonlinear equations of gas dynamics are solved in the framework of a numerical approach in order to study the stability of the steady mode of Rayleigh-Bénard convection in compressible, viscous and heat-conducting gases encapsulated in containers with no-slip boundaries and isothermal top and bottom walls. An initial linear temperature profile is assumed. A map of the possible convective modes is presented assuming the height of the region and the value of the temperature gradient as influential parameters. For a relatively small height, isobaric convection is found to take place, which is taken over… More >

Chetteti RamReddy^a,†, Teegala Pradeepa^a

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-10, 2017, DOI:10.5098/hmt.8.6

Abstract A numerical approach has been used to analyze the effects of homogeneous-heterogeneous reaction and nonlinear density temperature variation over a vertical plate in an incompressible micropolar fluid flow saturated Darcy porous medium. In addition, convective boundary condition is incorporated in a micropolar fluid model. The similarity representation for the set of partial differential equations is attained by applying Lie group transformations. The resulting non-dimensional equations are worked out numerically by spectral quasi-linearization method. Less temperature and wall couple stress coefficient, but more velocity, skin friction, species concentration, and heat transfer rate are noticed by enhancing More >

CH. Amanulla^a,b,* , N. Nagendra^a , M. Suryanarayana Reddy^b

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-11, 2017, DOI:10.5098/hmt.8.40

Abstract A theoretical and computational study of the magneto hydrodynamic flow and free convection heat transfer in an electro-conductive polymer on the external surface of a vertical permeable cone under radial magnetic field is presented. Thermal and velocity (hydrodynamic) slip are considered at the vertical permeable cone surface via modified boundary conditions. The Williamson viscoelastic model is employed which is representative of certain industrial polymers. The non-dimensional, transformed boundary layer equations for momentum and energy are solved with the second order accurate implicit Keller box finite difference method under appropriate boundary conditions. Validation of the numerical… More >

Elyazid Flilihi^a,† , Mohammed Sriti^a , Driss Achemlal^b , Mohamed El haroui^a

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-8, 2017, DOI:10.5098/hmt.9.23

Abstract A semi - analytical investigation is performed to analyze the thermal convection flow with a radiation flux and a variable internal heat generation along an inclined plate embedded in a saturated porous medium. The flow in the porous medium is modeled with the Darcy-Brinkman law taking into account the convective term, while the temperature field is obtained from the energy equation. These governing equations with the boundary conditions are first cast into a dimensionless form by using a unique similarity transformation and the resulting coupled differential equations are then solved numerically by a computational program More >

CH. Amanulla^a,b,* , N. Nagendra^a , M. Suryanarayana Reddy^b

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-9, 2017, DOI:10.5098/hmt.9.22

Abstract In this article, the combined theoretical and computational study of the magneto hydrodynamic heat transfer in an electro-conductive polymer on the external surface of a vertical truncated cone under radial magnetic field is presented. Thermal and velocity (hydrodynamic) slip are considered at the vertical truncated cone surface via modified boundary conditions. The Williamson viscoelastic model is employed which is representative of certain industrial polymers. The governing partial differential equations (PDEs) are transformed into highly nonlinear, coupled, multi-degree non-similar partial differential equations consisting of the momentum and energy equations via appropriate non-similarity transformations. These transformed conservation More >

G. C. Rana¹, R. C. Thakur²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.3, pp. 251-265, 2013, DOI:10.3970/fdmp.2013.009.251

Abstract In this paper, the effect of suspended particles on thermal convection in a compressible viscoelastic fluid hosted in a porous medium is considered. For the porous medium, the Brinkman model is employed with the Rivlin-Ericksen approach used in parallel to describe the rheological behaviour of the viscoelastic fluid. By applying a normal mode analysis method, a dispersion relation is derived and solved analytically. It is observed that the medium permeability, suspended particles, gravity field and viscoelasticity introduce oscillatory modes. For stationary convection, it is found that the Darcy-Brinkman number has a stabilizing effect whereas the More >

Ridha Djebali^1,2, Bernard Pateyron², Mohamed El Ganaoui³

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.4, pp. 293-308, 2012, DOI:10.3970/cmes.2012.088.293

Abstract We present in this study a numerical investigation of unsteady two-dimensional natural convection of an electrically conducting fluid in a square cavity under an externally imposed magnetic field. A temperature gradient is applied between the two opposing side walls parallel to y-direction, while the floor and ceiling parallel to x-direction are adiabatic. The flow is characterized by the Rayleigh number Ra raged in 103-106, the Prandtl number Pr ranged in 0.01-10, the Hartman number Ha determined by the strength of the imposed magnetic field ranged in 0-100 and its tilting angle from x-axis ranging from… More >

Ridha Djebali^1,2, Mohamed ElGanaoui³, Taoufik Naffouti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.6, pp. 499-527, 2012, DOI:10.3970/cmes.2012.084.499

Abstract A thermal lattice Boltzmann model for incompressible flow is developed and extended to investigate the natural convection flow in porous media under the effect of uniform magnetic field. The study shows that the flow behaviour is various parameters dependent. The Rayleigh number (Ra), Hartmann number (Ha), Darcy number (Da) and the medium inclination angle from the horizontal (Φ), the magnetic field orientation (ψ) and the medium porosity (ε) effects are carried out in wide ranges encountered in industrial and engineering applications. It was found that the flow and temperature patterns change significantly when varying these parameters. To confirm More >