Effect of Heat and Mass Transfer Through Diffusive Walls on Three-Dimensional Double-Diffusive Natural Convection

Abstract

A three-dimensional numerical study using vorticity-vector potential formulations based on the finite-volume method has been performed to investigate double-diffusive convection in a stack of cubic enclosures submitted to horizontal gradients of temperature and concentration. The flow is driven by conditions of constant temperature and concentration imposed along the two vertical side walls of each cubic enclosure, while the horizontal walls are diffusive in heat and mass. This numerical study is conducted for fixed Prandtl, Rayleigh, and Lewis numbers, Pr ¼ 10, Ra ¼ 10 5 and Le ¼ 10, buoyancy ratio N in the range [À2, 0], and for a range of heat and mass transfer diffusion coefficients. The results show that the effect of heat and mass diffusive walls differs between the case of thermally dominated flow and the compositionally dominated one. For thermally dominated flow, considering heat and mass diffusive walls results in a change from a structure with one inner core to a multicore structure and reduces the transverse velocity. On the other hand, for solutally dominated flow, an ''inverse transition'' from a multicell pattern to a unicellular one occurs, and the transverse velocity increases considerably.

Numerical simulation of three-dimensional double diffusive free convection flow and irreversibility studies in a solar distiller

“…They indicated that the doublediffusive flow in enclosures was strictly three-dimensional for a certain range of Rayleigh numbers, Lewis numbers and buoyancy ratios respectively. The same configuration was studied by Abidi et al [14] but with heat and mass diffusive horizontal walls. They mentioned that the effect of the heat and mass diffusive walls was found to reduce the transverse velocity for the thermal buoyancy-dominated regime and to increase it considerably for the compositional buoyancydominated regime.…”

“…This convection was largely studied for aiding or opposed temperature and concentration gradients. Studies on this subject can be found in several publications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. It was noted that, for a buoyancy number near the unity, an oscillatory flow takes place, caused by the interaction between thermal and compositional cells.…”

Heat and Mass Transfer and Entropy Generation Inside 3d Trapezoidal Solar Distiller

“…They mentioned that the 3D character is dominant for a certain range of parameters. Abidi et al (2008) studied the same configuration with heat and mass diffusive horizontal walls. The results show that there is a great difference between the cases of the compositionally dominated flow and thermally dominated one.…”

Effects of Buoyancy Parameter on Unsteady 3d Double Diffusive Convection in Molten Pb-Sn Alloys

“…The fluid in the diffusive interface is initially constant, but the interface changes into a new cell under a fixed condition. A 3D numerical analysis by using vorticity-vector potential formulations with finite-volume method has been performed to study the double-diffusive convection in a stack of cubic enclosures by Abidi et al (2008). Their findings showed that the effect of heat and mass diffusive walls differs between the case of thermally dominated flow and the compositionally dominated one.…”