Application of the Pin-Fin Heat Sink to Electronic Equipment [Study on Design Method for Flow-Guide Vanes]

Experimental and numerical studies were carried out to evaluate the effect of flow-guide vanes on air-intake velocity into the air-cooling heat sink, in the case of using a high performance but large pressure loss heat sink, such as a pin-fin array, for microprocessors having high power density. The flow-guide vanes were placed at the inlet portion of the heat sink in the spanwise direction. The pin-fin array used in the experiments was made of square shaped thin (0.2 mm) copper pins. Thermal resistance of the pin-fin array with and without flow-guide vane was measured, varying the upstream air velocity and the angle of the flow-guide vanes as a parameter. In the numerical simulation, the pressure loss characteristic based on the empirical formulas was applied. Two-dimensional laminar flow analyses using the finite differential method were performed. The parameters were the upstream air velocity, and the width and angle of the flow-guide vanes. The tendencies of the experimental and numerical analysis results showed good agreement, and it was found that the effect of the angle of flow-guide vanes on the intake air velocity was small. Also, the relation between the upstream velocity and actual intake velocity to the heat sink was discussed, and the design method for the optimum configuration of flow-guide vanes was proposed.