A Comparison of the Heat Transfer Performance of a Hexagonal Pin Fin with Other Types of Pin Fin Heat Sinks

In this study, the heat transfer performance of hexagonal pin-fin heat sinks is compared with various commonly used fin geometries in laminar forced Convection. Overall the numbers of models are carried out during this study 8 different model. In other words, 4 models in in-line arrays and the other in staggered arrays, which were round, square, rectangular and the case study hexagonal. In order to compare these various geometries, a set of standard conditions was required, the basic conditions used here (3.3mm) hydraulic diameter and (6.6mm) pitch were the same in all shapes. The ratio (PL/PW) was chosen to be one. The Analysis was simplified by some major assumptions. The fluid in the domain is air. The compressibility effects are ignored due to the low air speed. Heat transfer and fluid flow were assumed to be two-dimensional, with identical velocity and pressure distribution in the z-direction. The ratio of solid to fluid thermal conductivity for aluminum and air is around 8360, permitting the fins to be modeled as isothermal surfaces rather than conjugate solids. Numerical simulations are performed using FLUENT 6.3. The CFD simulations were carried out on a two-dimensional computational domain bounded by planes of symmetry parallel to the flow. The air approach velocity was in the range of 0.165 to 4.5m/s. A comparison of heat transfer performance and pressure drop is presented. In general, for the given pressure gradient and flow rate, the hexagonal fin geometry yield a higher Nusselt number in comparison to square fins, and a lower Nusselt number in comparison to circular fins. And it can be noted that the staggered hexagonal fin geometry gave the heat transfer performance like inline circular performance at most Reynolds numbers in the range considered here.