In this paper, we study the effect of a homogeneous longitudinal through flow on onset convection in horizontal porous layer saturated by binary fluid and heated from below or above. The boundaries are subjected to constant heat flux. investigation is made taking Soret into account. It found that case positive separation ratio when denser component moves toward cooler wall, has no stability threshold but exerts an orientating convective patterns. For negative ratio, strong destabilization...

In this paper we study by numerical simulation, the cooling of a solar cell forced convection in presence nanofluid. The inclined walls cavity are adiabatic but silicon cells subjected to constant heat temperature. nanofluid is introduced into with vertical speed and room equations governing flow hydrodynamics transfer described Navier-Stockes energy equations. For physical parameters Al2O3-Water nanofluid, use model Brinkman Wasp. finite elements method used solve system differential that...

In the present work, we study onset of double diffusive convection in vertical enclosures with equal and opposing buoyancy forces due to horizontal thermal concentration gradients (in case GrS/GrT=−1, where GrS GrT are, respectively, solutal Grashof numbers). We demonstrate that equilibrium solution is linearly stable until parameter RaT|Le−1| reaches a critical value, which depends on aspect ratio cell, A. For square cavity find value Rac|Le−1|=17 174 while previous numerical results give...

Technical Briefs Numerical Solution of a Flow due to Natural Convection in Horizontal Cylindrical Annulus M. C. Charrier-Mojtabi, Charrier-Mojtabi Laboratoire d'Ae´rothermique du C.N.R.S, 4 ter, route des Gardes, F 92190 Meudon, France Search for other works by this author on: This Site PubMed Google Scholar A. Mojtabi, Mojtabi J. P. Caltagirone Author and Article Information Heat Transfer. Feb 1979, 101(1): 171-173 (3 pages) https://doi.org/10.1115/1.3450911 Published Online: February 1,...

We present a numerical and analytical study of diffusive convection in rectangular saturated porous cell heated from below subjected to high frequency vibration. The configuration the Horton–Rogers–Lapwood problem is adopted. classical Darcy model shown be insufficient describe vibrational flow correctly. relevant system described by time-averaged Darcy–Boussinesq equations. These equations possess pure steady equilibrium solution provided vibrations are vertical. This linearly stable up...

The Poiseuille–Bénard flow (PBF) is studied by a two-dimensional numerical simulation for Prandtl number equal to 6.4 (that of water at 23 °C) and wide range Rayleigh (Ra) Reynolds (Re) numbers: Ra⩽6000 Re⩽3. two observed configurations are (1) thermally stratified Poiseuille (2) thermoconvective transversal rolls superimposed the basic flow. time evolution velocity components, spatial development rolls, their frequency, wavelength velocity, Nusselt number, together with stability map in...

Natural convection is investigated numerically and experimentally in a cylindrical annulus. The governing equations based on primitive variables are solved using Chorin’s method. In addition to the unicellular flows reported literature, depending initial conditions, bicellular observed for high Rayleigh numbers. bifurcation point determined numerically. velocity field measured by laser-Doppler anemometry an air-filled A perturbation solution also presented. experimental results good...

Thermogravitational separation has, until now, been used in differentially heated vertical cells, called thermogravitational columns (TGCs). The cell can be either a slit or an annular cavity whose two isothermal faces are maintained at different temperatures T1 and T2. In this study, we show contrary to what has done that it is possible carry out the of species binary mixture classical configuration Rayleigh-Bénard (horizontal from below with ratio psi>psi(mono)>0 above psi<0); obtain...

This work brings new insight to the question of heat transfer in near–critical fluids under Earth gravity conditions. The interplay between buoyant convection and thermoacoustic (piston effect) is investigated a two-dimensional non-insulated cavity containing local source, reproduce conditions used recent experiments. results were obtained by means finite-volume numerical code solving Navier–Stokes equations written for low-heat-diffusing near-critical van der Waals fluid. They show that...

Two-dimensional thermosolutal natural convection with Soret effect under the simultaneous action of vibrational and gravitational accelerations is investigated. We consider a porous cavity saturated by binary mixture adopt time-averaging formulation. For an infinite horizontal layer, stability analysis performed from which threshold determined. Numerical simulations, using pseudo-spectral Chebyshev collocation method, are to describe convective motion. The problem investigated for different...

In the present work, we study onset of double-diffusive convective regimes in a tilted rectangular cavity, filled with porous medium, saturated by binary fluid. Two opposite walls are maintained at different but uniform temperatures and concentrations while two other impermeable adiabatic. When thermal solutal buoyancy forces comparable intensity have signs, motionless regime linear temperature concentration profiles is solution problem. The first part consists stability analysis regime. We...

We present a numerical and analytical study of doubly diffusive convection driven by horizontal thermal solutal gradients in square rectangular enclosures with no-slip walls subjected to high-frequency vibration. The two vertical the enclosure are maintained at different but uniform temperatures concentrations while assumed be impermeable insulating. resulting system is described time-averaged Boussinesq equations. These equations possess quasi-equilibrium solution provided buoyancy forces...