Microneedles Rib Heat Sink Flow And Heat Transfer Simulation And Experimental

Owing to the advances of micro electronic technology, the power and circuit density of electronic devices have increased dramatically. As a result, more heat is generated and traditional air cooling is insufficient to dissipate such a high heat flux. Recent improvements in micro-fabrication technology have enabled the realization of a micro-scale cooling method based on different heat transfer mechanism. The arrays of micro pin fins arranged inside a micro channel constitute a heat transfer enhancement structure, which enable fluid to across the micro pin fins arrays to achieve a high thermal convective coefficient. This paper experimental and simulation investigate on flow resistance and heat transfer characteristics associated with the forced flow of de-ionized water through micro pin fins heat sinks.An experimental investigation on flow resistance characteristics of micro pin fins for water found that the density and shapes of pin fins have a significant effect on the pressure drop. The larger pin fins density will produce a greater pressure drop under the same height and shape of pin fins. The resistance characteristics influenced by shapes of pin fins is little at low flow volume, but increases with the increasing flow volume.When Re>600, the friction coefficient is close to constant. The swirl resistance of the working fluid is the largest for circle-shaped pin fins, diamond-shaped is the smallest. The end-wall effect increases the friction factor. The existing conventional scale correlations do not accurately predict the friction factor for micro pin fin arrays. The flow drag coefficient linear fitting equation is gotten based on experimental data.Heat transfer characteristics about the micro pin-fin arrays heat sinks have been experimentally investigated. The flow volume has a major influence on the temperature at the bottom of heat sink when the flow volume is small. As the flow volume increases, the average convective heat transfer coefficient increased. Reynolds number has a significant impact on heat transfer performance of heat sink. When Reynolds number is low, The end-wall effect has a significant impact on the heat transfer characteristics of heat sinks; when Reynolds numbers increase, the shapes of pin fins have more influence on the heat transfer performance of the heat sinks. The shapes of micro pin fins can enhance heat transfer because of the different disturbance caused by different shapes of pin fins. The elliptical and circular pin fins have the bigger disturbance affection on the flow of the working fluid, whereas the diamond pin fin have the smallest disturbance affection. An linear fitting equation about Nusselt number and Reynolds numbers is also gotten based on the experimental data.Flow resistance and heat transfer characteristics have been numerically simulated. The simulation data are good match the experimental data. Laminar flow model can be used to simulate flow resistance and heat transfer problem at the low Reynolds number.