Heat Transfer In Porous Channel Research Articles

Investigation of heat transfer in porous channels

PurposeThis paper aims to investigate the heat transfer in porous channels.Design/methodology/approachFinite element method is used to simulate the heat transfer in porous channels.FindingsThe number and width of channels play a key role in determining the heat transfer of the porous channel. The heat transfer is higher around the channel legs. Smaller base height is better to get higher heat transfer capability.Originality/valueThis study represents the original work to investigate heat transfer in a porous domain having multiple channels.

Erratum to: Thermodynamically Consistent Limiting Forced Convection Heat Transfer in a Asymmetrically Heated Porous Channel: An Analytical Study

Fluid transport and the associated heat transfer through porous media is of immense importance because of its numerous practical applications. In view of the widespread applications of porous media flow, the present study attempts to investigate the forced convective heat transfer in the limiting condition for the flow through porous channel. There could be many areas, where heat transfer through porous channel attain some limiting conditions, thus, the analysis of limiting convective heat transfer is far reaching. The primary aim of the present study is focused on the limiting forced convection analysis considering the flow of Newtonian fluid between two asymmetrically heated parallel plates filled with saturated porous media. Utilizing a few assumptions, which are usually employed in the literature, an analytical methodology is executed to obtain the closed-form expression of the temperature profile, and in the following the expression of the limiting Nusselt numbers. The parametric variations of the temperature profile and the Nusselt numbers in different cases have been shown highlighting the influential role of different performance indexing parameters, like Darcy number, porosity of the media, and Brinkman number of forced convective heat transfer in porous channel. In doing so, the underlying physics of the transport characteristics of heat has been delineated in a comprehensive way. Moreover, a discussion has been made regarding an important feature like the onset of point of singularity as appeared on the variation of the Nusselt number from the consideration of energy balance in the flow field, and in view of second law of thermodynamics.

POROUS SUBSTRATE EFFECTS ON THERMAL FLOWS THROUGH A REV-SCALE FINITE VOLUME LATTICE BOLTZMANN MODEL

In this paper, fluid flows with enhanced heat transfer in porous channels are investigated through a stable finite volume (FV) formulation of the thermal lattice Boltzmann method (LBM). Temperature field is tracked through a double distribution function (DDF) model, while the porous media is modeled using Brinkman–Forchheimer assumptions. The method is tested against flows in channels partially filled with porous media and parametric studies are conducted to evaluate the effects of various parameters, highlighting their influence on the thermo-hydrodynamic behavior.

Thermodynamically Consistent Limiting Forced Convection Heat Transfer in a Asymmetrically Heated Porous Channel: An Analytical Study

Fluid transport and the associated heat transfer through porous media is of immense importance because of its numerous practical applications. In view of the widespread applications of porous media flow, the present study attempts to investigate the forced convective heat transfer in the limiting condition for the flow through porous channel. There could be many areas, where heat transfer through porous channel attain some limiting conditions, thus, the analysis of limiting convective heat transfer is far reaching. The primary aim of the present study is focused on the limiting forced convection analysis considering the flow of Newtonian fluid between two asymmetrically heated parallel plates filled with saturated porous media. Utilizing a few assumptions, which are usually employed in the literature, an analytical methodology is executed to obtain the closed-form expression of the temperature profile, and in the following the expression of the limiting Nusselt numbers. The parametric variations of the temperature profile and the Nusselt numbers in different cases have been shown highlighting the influential role of different performance indexing parameters, like Darcy number, porosity of the media, and Brinkman number of forced convective heat transfer in porous channel. In doing so, the underlying physics of the transport characteristics of heat has been delineated in a comprehensive way. Moreover, a discussion has been made regarding an important feature like the onset of point of singularity as appeared on the variation of the Nusselt number from the consideration of energy balance in the flow field, and in view of second law of thermodynamics.

Analysis of heat transfer in oscillating flow through a channel filled with metal foam using computational fluid dynamics

A computational fluid dynamics analysis of forced convective heat transfer has been conducted numerically on the heat transfer of oscillating flow through a channel filled with metal foam subjected to constant heat flux. The flow field and heat transfer were modeled using the Darcy–Brinkman–Forchheimer-model with corresponding energy equations. The model was validated by comparing the numerical results with available experimental results for a channel filled with aluminum foam. The distribution of surface temperature on the heated plate and local Nusselt number were calculated. The effect of amplitude and frequency of oscillating flow on the heat transfer in porous channel were analyzed. The results of numerical analysis showed significant heat transfer enhancements by inserting metal foam in the channel. Furthermore, local Nusselt number increases with employing high amplitude and frequency of the oscillating air flow. Effects of thermal conductivity of metal foam and Reynolds number were also numerically analyzed. Results showed that an increase in thermal conductivity of the metal foam and Reynolds number can significantly increase the heat transfer. It is revealed that the proposed numerical model can efficiently provide useful information for the design of metal foam filled heat sinks with oscillatory inlet flow.

Convective heat transfer in porous channels with 90-deg turned flow

This study experimentally investigated the convective heat transfer and pressure drop in porous channels with 90-deg turned flow. Aluminum foams with a porosity of 0.93 were used. The size of the aluminum foams was fixed. Variable parameters were the ratio of the entry width to the porous sink height ( W j / H), the pore density of the aluminum foam (PPI, pore per inch) and the Reynolds number ( Re). Experimental results reveal that the wall temperature was maximal at the corner under perpendicular flow entry. It fell along the channel axis until x/ H was about 1.0, finally approaching a constant value. Parametric studies indicate that increasing Re increased the average Nusselt number ( Nu ¯ ) and the effects of W j / H and PPI on Nu ¯ were negligible. The friction factor ( C f) generally declined as Re increased, PPI decreased or W j / H increased. Besides, increasing W j / H or reducing PPI slightly increased Nu ¯ at a given pumping power. Additionally, the heat transfer and pressure drop in porous channels with straight flow were also measured for comparison.

An experimental study of heat transfer in oscillating flow through a channel filled with an aluminum foam

An experimental study has been conducted on the heat transfer of oscillating flow through a channel filled with aluminum foam subjected to a constant wall heat flux. The surface temperature distribution on the wall, velocity of flow through porous channel and pressure drop across the test section were measured. The characteristics of pressure drop, the effects of the dimensionless amplitude of displacement and dimensionless frequency of oscillating flow on heat transfer in porous channel were analyzed. The results revealed that the heat transfer in oscillating flow is significantly enhanced by employing porous media in a plate channel. The cycle-averaged local Nusselt number increases with both the kinetic Reynolds number Re ω and the dimensionless amplitude of flow displacement A 0. The length-averaged Nusselt number is effectively increased by increasing the kinetic Reynolds number from 178 to 874 for A 0 = 3.1–4.1. Based on the experimental data, a correlation equation of the length-averaged Nusselt number with the dimensionless parameters of Re ω and A 0 is obtained for a porous channel with L/ D h = 3.

Unsteady laminar hydromagnetic flow and heat transfer in porous channels with temperature‐dependent properties

The problem of unsteady laminar fully‐developed flow and heat transfer of an electrically‐conducting and heat‐generating or absorbing fluid with variable properties through porous channels in the presence of uniform magnetic and electric fields is formulated. The general governing equations which include such effects as magnetic field, electric field, porous medium inertia and heat generation or absorption effects are non‐dimensionalized and solved numerically by the implicit finite‐difference methodology. A representative set of numerical results for the transient and steady‐state velocity and temperature profiles, the skin‐friction coefficients at both the upper and lower walls of the channel as well as the heat transfer coefficient at the lower wall are presented graphically and discussed. Favorable comparisons with previously published work are performed and the results are in excellent agreement. A comprehensive parametric study is performed to show the effects of the Hartmann number, electric field parameter, inverse Darcy number, inertia parameter, heat generation or absorption coefficient, exponents of variable properties and the Eckert number on the solutions.