Begell House Inc.
Heat Transfer Research
HTR
1064-2285
45
3
2014
MIXED CONVECTION IN MHD MICROPOLAR FLUID WITH RADIATION AND CHEMICAL REACTION EFFECTS
199-218
D.
Srinivasacharya
Department of Mathematics, National Institute of Technology, Warangal-506004,
India
M.
Upendar
Department of Mathematics, NIT Warangal-506 004, AP, India
This article analyzes a mathematical model for the steady, mixed convection heat and mass transfer along a semi-infinite vertical plate embedded in a micropolar fluid in the presence of a first-order chemical reaction and radiation. A uniform magnetic field is applied normal to the plate. The plate is maintained with variable surface heat and mass fluxes. The governing nonlinear partial differential equations and their associated boundary conditions are transformed into a system of coupled nonlinear ordinary differential equations using similarity transformations and then solved numerically using the Keller box method. The numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. The nondimensional velocity, microrotation, temperature, concentration profiles, the rate of heat transfer, the rate of mass transfer, the skin friction coefficient, and the wall couple stress at the plate are presented graphically for different values of coupling number, Prandtl number, Schmidt number, magnetic parameter, radiation parameter, and chemical reaction parameter.
CONVECTIVE HEAT TRANSFER OF A SUTTERBY FLUID IN AN INCLINED ASYMMETRIC CHANNEL WITH PARTIAL SLIP
219-240
Noreen Sher
Akbar
DBS&H, CEME, National University of Sciences and Technology, Islamabad, Pakistan
Sohail
Nadeem
Department of Mathematics, Quaid-i-Azam University 45320, Islamabad 44000, Pakistan
The current article is concerned with the peristaltic flow of a Sutterby fluid in a straight asymmetric channel. The systems of equations have been formulated. Analysis was made of velocity and thermal slip situations. The stream function, pressure rise, heat transfer pressure gradient, and heat transfer coefficients are evaluated by means of the perturbation method. The graphs are presented and interpreted for various parameters.
LATTICE BOLTZMANN SIMULATION OF FORCED CONVECTION OVER AN ELECTRONIC BOARD WITH MULTIPLE OBSTACLES
241-262
Javad
Alinejad
Center of Excellence on Modeling and Control Systems (CEMCS) and Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran
Javad Abolfazli
Esfahani
Ferdowsi University of Mashhad
Forced convection heat transfer over an electronic board mounted with several shapes of obstacles, consisting of three cylinders and three cubes, is investigated using the lattice Boltzmann method (LBM). Incompressible flow of field through the obstacles over a sheet is assumed. The simulations are performed at Pr = 0.71. Studies are carried out for flow, with Reynolds numbers ranging from 250 to 1000. Uniform heat fluxes through the base of obstacles are assumed. Results show that LBM is suitable for the study of heat transfer in forced convection problems. Results indicate that an increase in Reynolds number yields to the removal of a higher quantity of energy from obstacle faces. Results also show that reducing the distance between obstacles makes the flow deviate and accelerate in the vicinity of faces and causes an increase in the rate of convective heat transfer from obstacles.
AN EFFICIENT ANALYTICAL SOLUTION STRATEGY FOR MULTIDIMENSIONAL HEAT CONDUCTION PROBLEMS
263-278
Mohammad
Asif
Department of Chemical Engineering, King Saud University, PO Box 800, Riyadh 11421, Saudi Arabia
A wide variety of multidimensional heat conduction problems of interest involve a first-order dissipation term with either homogeneous or nonhomogeneous boundary conditions. An important class of similar problems of practical interest quite often also occurs in the mass diffusion that involves a diffusion-impeded chemical reaction inside a porous catalyst pellet. Developing an efficient analytical solution strategy for such problems is important in view of the fact that different analytical solutions of the same problem can exhibit widely different convergence behavior depending on the solution methodology. In the present study, a three-dimensional rectangular parallelepiped is taken as a case study. The governing partial differential equation with nonhomogeneous boundary conditions is solved using two different approaches. An analytical solution is first obtained using the standard commonly used decomposition approach. The application of the particular solution approach is also detailed here. The two-dimensional problem is considered first, extending the same analysis later to the three-dimensional problem. Owing to relevance to the engineering design and optimization, expressions for the efficiency or the effectiveness factor are obtained in all cases, and a comparison is carried out. The particular solution approach offers much better convergence behavior than the decomposition approach and than others reported in the literature so much so that the computing time for the same level of accuracy in some cases is found to differ by several orders of magnitude.
NUMERICAL SIMULATION OF NATURAL CONVECTION AROUND AN OBSTACLE PLACED IN AN ENCLOSURE FILLED WITH DIFFERENT TYPES OF NANOFLUIDS
279-292
Mohammad
Hemmat Esfe
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Ali Akbar Abbasian
Arani
Department of Mechanical Engineering, University of Kashan, Kashan 87317-53153, Iran
Arash
Karimipour
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Isfahan, Iran
Seyed Sadegh Mirtalebi
Esforjani
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Isfahan, Iran
The present numerical study deals with natural convection in an enclosure with a heated cylindrical block filled with nanofluid. The governing equations have been discretized using the finite volume method, and the SIMPLE algorithm has been used to couple velocity and pressure fields. The effect of the Rayleigh number, type, solid volume fraction of nanoparticles, radius, and position of the hot body is studied, and obtained results are presented in the form of streamline and isotherm plots, a Nusselt diagram, and comparative tables. Water, Cu−water, and Al2O3−water have been utilized as working fluids. In this study, the particle diameters of Cu and Al2O3 nanoparticles are 90 and 47 nm, respectively. On the basis of the results, increasing solid volume fraction and Ra number causes a noticeable enhancement in the rate of heat transfer. Also, increasing the radius of the hot circular cylinder, differences in values of Nusselt number between base fluid and nanofluid significantly increase.