Forced convection on heat exchangers yields to higher heat exchange coefficient and so permits to limit the temperature difference between air and the evaporator. Higher energy performances of the refrigerating cycle is affordable compared to natural convection evaporators. In Europe, many refrigerators and freezers integrate natural convection heat exchangers. Making a review of the actual ene...

This article is concerned with the shape of small devices used to control the heat flowing between a solid and a fluid phase, usually called fin. The temperature along a fin in stationary regime is modeled by a one-dimensional Sturm-Liouville equation whose coefficients strongly depend on its geometrical features. We are interested in the following issue: is there any optimal shape maximizing t...

This article is concerned with the shape of small devices used to control the heat flowing between a solid and a fluid phase, usually called fin. The temperature along a fin in stationary regime is modeled by a one-dimensional Sturm-Liouville equation whose coefficients strongly depend on its geometrical features. We are interested in the following issue: is there any optimal shape maximizing t...

One of the primary ways to enhance heat transfer rate is to use extended surfaces or fins. The heat transfer mechanism of fin is to conduct heat from the heat source to fin surface by its thermal conduction, and then dissipates it to surrounding medium by convection. Most common application areas of fins are in combustion engines, heat exchangers and cooling of electronic equipments. Early stud...

Three-dimensional CFD simulations are carried out to investigate heat transfer and fluid flow characteristics of a four-row plain fin-and-tube heat exchanger using the Commercial Computational Fluid Dynamics Code ANSYS CFX 12.0. Heat transfer and pressure drop characteristics of the heat exchanger are investigated for Reynolds numbers ranging from 400 to 2000. Fluid flow and heat transfer are s...

The objectives of this study are to provide experimental data and a correlation that can be used in the optimal design of an evaporator under frost conditions. In the present study, we tested both a single stage and a two-stage evaporator with a variation of operating parameters and fin geometry under frost conditions. The effects of tube space and fin alignment on the heat transfer performance...

This study presents the numerical simulation of optimum pin-fin heat sink with air impinging cooling by using Taguchi method. 9 L ( 4 3 ) orthogonal array is selected as a plan for the four design-parameters with three levels. The governing equations are discretized by using the control-volume-based-finite-difference method with a power-law scheme on the non-uniform staggered grid. We solved th...

The optimum design of the heat sink by using differential evolution (DE) method is discussed in the present paper. The DE strategy (DE/ best/ 1/exp) is used here because this strategy is best strategy for heat transfer applications [1]. The main procedures for the heat sink optimization is found the minimum thermal resistance (maximize the heat transfer per unit volume) of the heat sink in orde...

An analytical solution to the transient heat conduction for a two dimensional cylindrical fin with general boundary conditions is obtained by the principle of superposition and separation variables. In the analysis, homogeneous material properties and thickness, the convective heat transfer coefficient, the ambient temperature and the fin properties are assume to be constant. The closed form tr...

In the present paper, natural convection fluid flow and heat transfer in a square cavity heated from below and cooled from sides and the ceiling with a thin fin attached to its hot bottom wall is investigated numerically. The right and the left walls of the cavity, as well as its horizontal top wall are maintained at a constant temperature Tc, while the bottom wall is kept at a constant tempera...