Papers by Keyword: Vertical Plate

Abstract: The paper examines the combined effects of Hall current, buoyancy forces, thermal radiation, thermo-diffusion and fluid rotation on an unsteady hydromagmetic boundary layer flow with heat and mass transfer over an impulsively moving vertical plate embedded in a porous medium. Base on some realistic simplified assumptions, the governing equations of momentum, energy and chemical species concentration are obtained and tackled analytically using Laplace transform technique. The numerical values of primary and secondary fluid velocities, fluid temperature and species concentration are displayed graphically while those of skin friction coefficient, Nusselt number and Sherwood number are presented in tabular form for different values of pertinent flow parameters.

Abstract: This article investigates the magnetohydrodynamic mixed convective heat, and mass transfer flow of an incompressible, viscous, Boussinesq, electrically conducting fluid from a vertical plate in a sparsely packed porous medium in the presence of thermal radiation and an nth order homogeneous chemical reaction between the fluid and the diffusing species numerically. In this investigation, the fluid and porous properties like thermal and solutal diffusivity, permeability and porosity are all considered to be vary. The governing non-linear PDE's for the fluid flow are derived and transformed into a system of ODE's using an appropriate similarity transformation. The resultant equations are solved numerically using shooting technique and Runge-Kutta integral scheme with the help of Newton-Raphson algorithm in order to know the characteristics of the fluid for various non-dimensional parameters which are controlling the physical system graphically. The results of the numerical scheme are validated and a numerical comparison has been made with the available literature in the absence of some parameters and found that in good agreement. Nomenclature

Abstract: An analytical study of transient natural convective flow of a viscous incompressible optically thick radiating fluid past a moving vertical plate with ramped heat and mass fluxes in the presence of thermal radiation is performed. Exact solution of the governing equations under Boussinesq approximation, is obtained in closed form by Laplace transform technique. The expressions for the shear stress and at the plate temperature and concentration are also derived. The velocity profiles, temperature and species concentration are studied as functions of different physical parameters like radiation parameter, thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. The physical aspects of the problem are discussed.

Abstract: In this manuscript, we have investigated the influence of radiation absorption on an unsteady MHD convective heat and mass transfer flow of a Newtonian fluid past a vertical porous plate in the presence of thermal radiation and chemical reaction. The non dimensional governing equations have been solved by using a multiple perturbation method, subject to the corresponding boundary conditions. The effects of various physical parameters such as velocity, temperature and concentration are studied through graphs. The expressions for local skin friction, Nusselt number and Sherwood number are derived and discussed with the help of a table. It is noticed that velocity increases when an increase in modified Grashof number Gm, radiation absorption parameter χ, Sorret number S₀, time t whereas it decreases when an increase in Schmidt number Sc, chemical reaction parameter Kr and radiation parameter F. Temperature increases with an increase in radiation parameter χ and Sorret number S₀ whereas it decreases with an increase in chemical reaction parameter Kr, F and ϕ. Concentration is observed to be decreased when chemical reaction parameter Kr and Schmidt number Sc increase whereas it increases with an increase in Sorret number S₀. Skin friction increases with an increase modified Grashof number Gm, radiation parameter χ and Sorret number S₀ whereas it has reverse effect in the case of Schmidt number Sc, chemical reaction parameter Kr. Nusselt number increases with an increase in Sc, S₀, χ whereas it has reverse effect in the case of Kr. Sherwood number gets decreased when Sc, χ and Kr both are increased whereas it has shown revere effect in the case of S₀.

Abstract: Theoretical analysis of unsteady magnetohydrodynamic free convection flow of a viscous incompressible radiative fluid past an infinite vertical plate with constant heat and mass flux is presented. The dimensionless governing linear partial differential equations have been solved using the Laplace transform technique. The exact solutions for the velocity, temperature and concentration fields are derived. The effects of radiation, magnetic field and buoyancy ratio parameters on the velocity and temperature fields are discussed through graphs. It is found that the velocity increases with increasing radiation parameter whereas it decreases with increasing magnetic field parameter for buoyancy assisted flows.

Abstract: A frosting test bench was designed, and unsteady frosting on vertical plate surface was dynamically described with liquid nitrogen as working medium under natural convection conditions. The variation of frost thickness was analyzed, and the flow state of moist air and temperature distribution near the vertical plate were described. The experimental results show the unsteady frosting of vertical plate surface under natural convection and cryogenic condition actually includes several steps: formation of frost crystals, growth of frost crystals and growth of frost layer. The initial frosting rate is large, but the rate decreases as time goes on until the frost layer thickness is unchanged. Moist air conducts a top-down flow near the vertical plate, and the rest of moist air flows into the main flow. The temperature of moist air decreased systematically along the tangential direction of vertical plate from top to bottom and along the normal direction of vertical plate from far to vertical plate surface.

Abstract: Steady, two dimensional mixed convection laminar boundary layer flow of incompressible nanofluid along a permeable vertical semi-infinite flat plate with magnetic field effects has been investigated numerically. The resulting govering equations (obtained from the boussinesq) with associated boundary conditions are solved, using a robust, extensively validated, Galerkin Finite Element Method for different types of spherical shaped metal oxide nanoparticles with two different ratios of the nanolayer thickness to the original particle radius (0.02 or 0.1). The effects of the parameters governing the problems are discussed and shown graphically. The present study is of immediate interest in next-generation solar film collectors, heat exchangers technology, material processing exploiting vertical surfaces and all those processes which are highly affected with heat transfer.

Abstract: A set of experiments is done to study the phenomenon of free convection heat transfer from an isothermal vertical flat plate embedded in a saturated porous medium in steady state condition. The porous medium consisting of 0.8 cm spheres. The aspect ratio of the isothermal flat plate, H/W, is equal to 2. Where H is the height and W is the width of the vertical plate. The investigations were cared out for Darcy modified Rayleigh number between 100 and 500. The results indicate that heat transfer increases linearly with increasing the Darcy modified Rayleigh number. In addition, the present results are in good agreement with the higher-order boundary layer theory obtained by Cheng and Hsu [1].