Effect of Porous Media Properties on Heat Transfer in Triangular Porous Ducts With Iso-Flux Walls

2011 ◽  
Author(s):  
S. Negin Mortazavi ◽  
Fatemeh Hassanipour
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Temperature Distribution ◽  
Boundary Conditions ◽  
Constant Heat Flux ◽  
Triangular Channel ◽  
Wall Boundary Conditions ◽  
Porosity And Permeability ◽  
The Galerkin Method ◽  
Energy Equations

This study presents an analysis of forced convection in a porous triangular channel. The flow is assumed to have constant properties and the porous channel is an isotropic matrix. The flow is laminar and fully developed and the boundary conditions are fixed with a constant heat flux. In this paper, the accurate analytical solutions are presented to obtain the effects of porosity and permeability on the velocity and temperature distribution in a triangular channel along with the friction factor fRe, and Nusselt number NuH. The momentum and energy equations include the term of Darcy, effective viscosity and apex angel. So, the flow velocity and temperature distribution have been investigated in porous media with different properties. The Galerkin method has been applied to solve the equations accurately by considering a weight function for no slippery and isothermal wall boundary conditions. Temperature and velocity distribution and heat transfer coefficient have been obtained and compared with the same flow situation in rectangular channels.

A Heat Transfer in Iso-Thermal Triangular Channel Filled With Porous Media

2012 ◽  
Author(s):  
S. Negin Mortazavi ◽  
Fatemeh Hassanipour
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Nusselt Number ◽  
Temperature Distribution ◽  
Boundary Conditions ◽  
Forced Convection ◽  
Constant Temperature ◽  
Analytical Solutions ◽  
Apex Angle ◽  
Triangular Channel

This study presents an analysis of forced convection in a porous triangular channel. The flow is laminar, fully developed and assumed to have constant properties. The porous channel has an isotropic matrix and the boundary conditions are fixed with a constant temperature. In this paper, accurate analytical solutions are presented to determine the effects of apex angle and porous media properties on the temperature distribution in a triangular channel along with the Nusselt number NuT.

Effect of Porous Media Properties on Heat Transfer in Triangular Porous Duct

2012 ◽  
Author(s):  
S. Negin Mortazavi ◽  
Fatemeh Hassanipour
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Nusselt Number ◽  
Temperature Distribution ◽  
Boundary Conditions ◽  
Analytical Solutions ◽  
Series Solution ◽  
Apex Angle ◽  
Average Temperature ◽  
Triangular Channel

This study presents an analysis of forced convection in a porous triangular channel. The flow is laminar, fully developed and assumed to have constant properties. The porous channel has an isotropic matrix and the boundary conditions are fixed with constant temperature. In this paper, accurate analytical solutions are presented to determine the effects of apex angle and porous media properties on the velocity and temperature distribution in a triangular channel along with the friction factor fRe, and Nusselt number NuT. The presentaion includes numerical features of the exact series solution using Brinkman’s model. Numerical results for dimensionless average temperature and velocity are presented for various porosities, permeabilities and apex angles.

scholarly journals Heat Transfer Enhancement in Microchannel Flow: Presence of Microparticles in a Fluid

2010 ◽  
Author(s):  
Awad B. S. Alquaity ◽  
Salem A. Al-Dini ◽  
Evelyn N. Wang ◽  
Shahzada Z. Shuja ◽  
Bekir S. Yilbas ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Pressure Drop ◽  
Phase Change ◽  
Constant Heat Flux ◽  
Working Fluid ◽  
Microchannel Flow ◽  
Carrier Fluid ◽  
Volume Fractions ◽  
Energy Equations

In the present study, a numerical model was developed for laminar flow in a microchannel with a suspension of microsized phase change material (PCM) particles. In the model, the carrier fluid and the particles are simultaneously present, and the mass, momentum, and energy equations are solved for both the fluid and particles. The particles are injected into the fluid at the inlet at a temperature equal to the temperature of the carrier fluid. A constant heat flux is applied at the bottom wall. The temperature distribution and pressure drop in the microchannel flow were predicted for lauric acid microparticles in water with volume fractions ranging from 0 to 8%. The particles show heat transfer enhancements by decreasing the temperature distribution in the working fluid by 39% in a 1 mm long channel. Meanwhile, particle blockage in the flow passage was found to have a negligible effect on pressure drop in the range of volume fractions studied. This work is a first step towards providing insight into increasing heat transfer rates with phase change-based microparticles for applications in microchannel cooling and solar thermal systems.

Unsteady and porous media flow of reactive non-Newtonian fluids subjected to buoyancy and suction/injection

2015 ◽  
Vol 25 (7) ◽  
pp. 1682-1704 ◽  
Author(s):  
Tirivanhu Chinyoka ◽  
Daniel Oluwole Makinde
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Boundary Conditions ◽  
Flow Velocity ◽  
Flow System ◽  
Finite Difference Methods ◽  
Porous Media Flow ◽  
Convective Boundary Conditions ◽  
Convective Boundary ◽  
Content Type

Purpose – The purpose of this paper is to examine the unsteady pressure-driven flow of a reactive third-grade non-Newtonian fluid in a channel filled with a porous medium. The flow is subjected to buoyancy, suction/injection asymmetrical and convective boundary conditions. Design/methodology/approach – The authors assume that exothermic chemical reactions take place within the flow system and that the asymmetric convective heat exchange with the ambient at the surfaces follow Newton’s law of cooling. The authors also assume unidirectional suction injection flow of uniform strength across the channel. The flow system is modeled via coupled non-linear partial differential equations derived from conservation laws of physics. The flow velocity and temperature are obtained by solving the governing equations numerically using semi-implicit finite difference methods. Findings – The authors present the results graphically and draw qualitative and quantitative observations and conclusions with respect to various parameters embedded in the problem. In particular the authors make observations regarding the effects of bouyancy, convective boundary conditions, suction/injection, non-Newtonian character and reaction strength on the flow velocity, temperature, wall shear stress and wall heat transfer. Originality/value – The combined fluid dynamical, porous media and heat transfer effects investigated in this paper have to the authors’ knowledge not been studied. Such fluid dynamical problems find important application in petroleum recovery.

Numerical Analysis of Temperature Distribution in a Three-Dimensional Image-Based Hand Model

2010 ◽  
Author(s):  
Hongwei Shao ◽  
Ying He ◽  
Lizhong Mu
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Porous Media ◽  
Temperature Distribution ◽  
Interpolation Method ◽  
Local Equilibrium ◽  
Human Hand ◽  
Anatomic Structure ◽  
Blood Flow Modeling ◽  
Large Vessels

In the present study, a simulation has been developed to investigate the blood and temperature distribution in the human hand. The simulation consists of image-based mesh generation, blood flow modeling in large vessels, and finite element analysis of heat transfer in tissues based on the porous media theory. In order to reconstruct a real geometric mesh model of the human hand, sequential MR images of a volunteer’s hand was taken firstly. Furthermore, a MATLAB program was developed to detect the edge information of the target by applying several image preprocessing operators. Finally, a FORTRAN program based on the transfinite interpolation method was developed to generate mesh from the preprocessed images automatically, and the positions of simplified bones and vessels were set according to the anatomic structure. The blood flow in large vessels adopted in this study was provided from the one-dimensional simulation of blood circulation in the upper limb, which was completed by He [1]. On the other hand, blood flow perfused in solid tissues through the micro vessels was expressed by Darcy model. The heat transfer in tissues was described by the energy equation for porous media with assuming that a local equilibrium was achieved between the blood and tissue phase. The primary results for the distribution of the blood flow perfused in tissues and temperature were obtained in this study, and they were similar to the real state of the human hand. The improvement of this simulation will be the next work.

On Effects of Temperature Boundary Conditions on Heat Transfer in Turbulent Low-Prandtl-Number Flows

2020 ◽  
Author(s):  
Ivan Otic
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Heat Flux ◽  
Boundary Conditions ◽  
Constant Heat Flux ◽  
Constant Heat ◽  
Flux Boundary Condition ◽  
Large Eddy ◽  
Heat Flux Boundary Condition ◽  
Effects Of Temperature

Abstract One important issue in understanding and modeling of turbulent heat transfer is the behavior of fluctuating temperature close to the wall. Common engineering computational approach assumes constant heat flux boundary condition on heated walls. In the present paper constant heat flux boundary condition was assumed and effects of temperature fluctuations are investigated using large eddy simulations (LES) approach. A series of large eddy simulations for two geometries is performed: First, forced convection in channels and second, forced convection over a backward facing step. LES simulation data is statistically analyzed and compared with results of direct numerical simulations (DNS) from the literature which apply three cases of heat flux boundary conditions: 1. ideal heat flux boundary condition, 2. non-ideal heat flux boundary condition, 3. conjugate heat transfer boundary condition. For low Prandtl number flows LES results show that, despite very good agreement for velocities and mean temperature, predictions of temperature fluctuations may have strong deficiencies if simplified boundary conditions are applied.

Experimental Study of Internal Forced Convection of Ferrofluid Flow in Porous Media

2014 ◽  
Vol 348 ◽  
pp. 139-146 ◽  
Author(s):  
Ashkan Sehat ◽  
Hani Sadrhosseini ◽  
M. Behshad Shafii
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Experimental Study ◽  
Porous Media ◽  
Temperature Distribution ◽  
Pressure Drop ◽  
Forced Convection ◽  
Volume Fraction ◽  
Flow In Porous Media ◽  
Tetra Methyl Ammonium Hydroxide

This work presents an experimental study of the effect of a magnetic field on laminar forced convection of a ferrofluid flowing in a tube filled with permeable material. The walls of the tube are subjected to a uniform heat flux and the permeable bed consists of uniform spheres of 3-mm diameter. The ferrofluid synthesis is based on reacting iron (II) and iron (III) in an aqueous ammonia solution to form magnetite, Fe3O4. The magnetite is mixed with aqueous tetra methyl ammonium hydroxide, (CH3)4NOH, solution. The dependency of the pressure drop on the volume fraction, and comparison of the pressure drop and the temperature distribution of the tube wall is studied. Also comparison of the wall temperature distribution, convection heat transfer coefficient and the Nusselt numbers of ferrofluids with different volume fractions is investigated for various Reynolds numbers (147 < Re < 205 ). It is observed that the heat transfer is enhanced by using a porous media, increasing the volume fraction had a similar effect. The pressure coefficient decreases for higher Reynolds number. The effect of magnetic field in four strategies, named modes, on ferrofluid flow through the porous media is presented.

scholarly journals Benchmark Studies for the Generalized Streamwise Periodic Heat Transfer Problem

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Steven B. Beale
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Transfer Problem ◽  
Mixed Boundary ◽  
Mixed Boundary Conditions ◽  
Wall Boundary Conditions ◽  
Engineering Problems ◽  
Complex Engineering ◽  
The Common ◽  
Periodic Heat

This is a comparison of calculations performed with a scheme for handling streamwise-periodic boundary conditions with known solutions to the common problem of fully developed heat transfer in a plane duct. Constant value, constant flux, mixed boundary conditions, and linear wall flux (conjugate heat transfer) are all considered. Agreement is, in every case, near exact showing that the methodology may be applied with confidence to complex engineering problems with a variety of thermal wall boundary conditions.

Sign in / Sign up

Export Citation Format

Share Document