NUMERICAL ANALYSIS OF CONVECTIVE HEAT TRANSFER IN A PIN FIN HEAT SINK UNDER NON UNIFORM HEAT FLUX CONDITIONS

摘要

In this study, numerical simulations of the flow hydrodynamics and heat transfer of a heat sink with Diamond shaped pin fins in a staggered array were carried out using FLUENT 6.3 code. The heat sink is bonded flat against the back face of a 10 mm thick silicon mirror. Conjugated heat transfer in the mirror and the heat sink is considered. The heat sink is 47 arrays of 8 staggered square pin fins, having 1.7mm in width and 1.6 mm in height. The pin fins are equidistantly spaced with a fluid passage width 0.35 mm. Therefore the cross section is 0.35×1.6 mm~2. Water was employed as the cooling liquid and the fin's material is cooper. Inlet mass flow rate was varied from 0.27 to 2.95 l/min. The first order k-ε turbulence model was used for flow modeling in the micro-channels. A Gaussian distribution of the heat flux density, with a maximum at 350 W/cm~2, is applied as a boundary condition on the front surface of the mirror. This distribution corresponds to the light beam at the outlet of the storage booster of electrons in Synchrotron SOLEIL facility. The numerical modeling has been validated by comparison the results with the data provided by the experimental study conducted by A. Hamza (2013). The final objective of this study is to propose an optimal geometry and arrangement of the pin-fins which leads to a homogeneous temperature distribution within the mirror. Reduction of the temperature gradient inside the optics will improve the quality of photon beam-line derived from the Synchrotron SOLEIL.