الفهرس 
Chapter One: IntroductionOnly 14 pages are availabe for public view
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Abstract
Heat sinks are devices used to dissipate heat generated in electric and electronic components to keep the optimum operating temperature. Many configurations are used ranging from mini to large scale. The plate-fin heat sink is a common used configuration. Its ease of fabrication andsmall pressure DROP are appreciated features of this type of heat sinks. Many parameters affect the thermal performance of the plate-fin heat sink. The fin pitch, height, shape, and cooling medium, type and properties are important parameters.
The present study investigates the effect of fin pitch, fin configuration and air velocity on the plate-fin thermal performance both experimentally and analytically. Some previous researchers studied the performance of plate-fin heat sinks with a proposed fin cross-cut. Herein, the cut vertical depth is considered a parameter considered a parameter as an enhancement tool for heat dissipation from the fins. A test rig to simulate a heat sink mounted on the top of a computer processor is designed and installed. A Testo-type hotwire is used to measure the air velocity along the air duct cross-section, in addition to thermocouples to measure heat sink base temperature and local air temperaturevariations.
The results showed an increase of air average temperature as air proceeds from inlet to exit and the wider the pitch the lower is the air operating temperature. Similarly, increasing the air velocity, for the same pitch, reduces the air average temperature, and hence improves the heat transfer on the expense of pumping power. Moreover, the results indicate that the cut significantly improves the heat sink performance as a result of enhancing the heat transfer coefficient.The full cut showsbetter behavior than the partial cut due tothe full break down and then redeveloping of the boundary layer compared to the partialeffect in case of partial cut depth. Heat transfer enhancements were 15 ℅ in case of having a full cut at the lowest velocity examined and 18.7 ℅ at the highest velocity for the same pitch compared to the no-cut case. When the cut locations varied from the middle towards 0.75 of plate length, a slight heat enhancement was noticed, 2.1 % to 2.7 %,for the lowest and highest velocities, respectively. Hence, the effect of cut location shows less importance compared to the cut depth.