Performance of Shrouded Pin-Fin Heat Sinks for Electronic Cooling

The objective of this study is to analyze the performance of a cylindrical pin-fin heat sink in laminar forced convection. The mathematical models are presented for predicting thermal and hydraulic resistances for both in-line and staggered arrangements. Analytical/empirical correlations of friction and heat transfer coefficients are used in the analysis. The analyses are performed by using parametric variation of resistances. The effects of thermal joint, spreading, and contact resistances as well as the thermal conductivity on the overall thermal performance are examined. For a given size and heat load, it is observed that the overall performance of a pin-fin heat sink depends on a number of parameters including the dimensions of the pin-fins, pin density, longitudinal and transverse spacings, interface material, location and size of heat sources, method of manufacturing, type of heat-sink material, approach velocity, and arrangement of pins. It is also observed that the thermal resistance decreases whereas pressure drop increases with an increase in approach velocity, pin diameter, and pin density. Nomenclature Ab = area of the base plate ≡ L × W, m2 Ac = cross-section or contact area of a single pin, m2 Afin = surface area of a single pin, m2 Ahs = surface area of heat sink, m