Nikita S. Gibanov

Convective heat transfer of ferrofluid in a lid-driven cavity with a heat-conducting solid backward step under the effect of a variable magnetic field

ABSTRACT The effect of variable magnetic field on the mixed convective flow of a ferrofluid within a lid-driven cavity has been analyzed numerically. A heat-conducting solid block is located in the bottom part of the cavity. Governing partial differential equations have been formulated taking into account that the magnetic source is a point source located over the moving lid. Analysis has been performed for a wide range of Hartmann number, nanoparticles volume fraction, and magnetic number. It has been found that the growth of the magnetic number leads to the heat transfer enhancement.

Unsteady natural convection in a cubical cavity with a triangular heat source

Purpose The purpose of this paper is to study natural convective fluid flow and heat transfer inside a cubical cavity having a local heat source of constant temperature. Design/methodology/approach The cubical cavity is cooled from two vertical opposite walls and heated from the local heater mounted on the bottom wall, while the rest walls are adiabatic. The governing equations formulated in dimensionless vector potential functions and vorticity vector have been solved using implicit finite difference method of the second-order accuracy. The effects of the Rayleigh number (Ra = 1e+04 – 1e+06), heat source position (l/L = 0.05 – 0.35) and dimensionless time (0 < tau < 100) on velocity and temperature fields, streamlines, isotherms and average Nusselt number at the heat source surface have been analyzed. Findings It is found that the extreme left position of the heater (l/L = 0.05) illustrates more essential cooling of the cavity where the thermal plume over the heat source is suppressed by low temperature waves from the cold vertical walls. Originality/value The originality of this work is to analyze transient 3D natural convection in a cubical cavity with a heater of triangular shape and compare obtained 3D data with 2D results. It should be noted that for numerical simulation, the authors used vector potential function and vorticity vector that for transient problems allows to reduce the computational time. The results would benefit scientists and engineers to become familiar with the analysis of transient convective heat and mass transfer in 3D domains with local heaters, and the way to predict the properties of convective flow in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors, ventilation, air-conditioning, etc.

Effect of uniform inclined magnetic field on natural convection and entropy generation in an open cavity having a horizontal porous layer saturated with a ferrofluid

ABSTRACT Numerical analysis of natural convection combined with entropy generation in a square open cavity partially filled with a porous medium has been performed for a ferrofluid under the effect of inclined uniform magnetic field. Governing equations with corresponding boundary conditions formulated in dimensionless stream function and vorticity using Brinkman–extended Darcy model for porous layer have been solved numerically using finite difference method. An influence of key parameters on ferrofluid flow and heat transfer has been analyzed. It has been found that an inclusion of spherical ferric oxide nanoparticles can lead to a diminution of entropy generation in the case of similar flow and heat transfer structures.

Mixed Convection in a Ventilated Cavity Filled with a Triangular Porous Layer

Mixed convection in a square cavity having a triangular porous layer and a local heater has been investigated numerically. The governing partial differential equations with corresponding boundary conditions have been solved by the finite difference method using the dimensionless stream function, vorticity and temperature formulation. The effects of the Richardson number (

Natural convection of micropolar fluid in a wavy differentially heated cavity

{ Ri} = 0.01 - 10

Convective heat transfer in a lid-driven cavity with a heat-conducting solid backward step under the effect of buoyancy force

Ri=0.01-10), Darcy number (

Natural convection in a cubical cavity with different heat source configurations

{ Da} = 10^{-7} -10^{-1}