The Influence of the Thermal Conductivity on the Heat Transfer Performance in a Heat Sink

Abstract

An extensive numerical analysis of the temperature distribution and fluid flow in a heat sink currently being used for cooling desktop computers was conducted, and demonstrated that if the base of a heat sink was fabricated as a heat pipe instead of a solid material, the heat transfer performance could be significantly increased. It was shown that as the heat sink length increases, the effect of the thermal conductivity of the base on the heat transfer performance increases to be a predictable limit. As the thermal conductivity is increased, the heat transfer performance of heat sinks is enhanced, but cannot exceed this limit. When the thermal conductivity increases to 2,370 W/m-K, the heat transfer performance of the heat sinks will be very close to the heat transfer performance obtained assuming a base with infinite thermal conductivity. Further increases in the thermal conductivity would not significantly improve the heat transfer performance of the heat sinks.

Heat-spreading analysis of a heat sink base embedded with a heat pipe

“…Ma and Peterson [4] have used an effective thermal conductivity to model the heat sink base embedded with a heat pipe and obtained a good agreement with experimental data. With a given forced convection for a heat sink, the heat transfer coefficient is given.…”

“…From the data obtained experimentally by Ma and Peterson [4], the effective convective heat transfer coefficient was determined for the fins by Eq. (5).…”

“…Ma and Peterson [4] conducted an investigation of the effect of thermal conductivity on the heat transfer performance of a heat sink, where a configuration shown in Fig. 1 was considered.…”

Forced Heat Convection of Wavy Fin Channel

“…As shown in Fig. 2-a, the airflows entered the entry plenum chamber (1) in which the meshes and honeycomb were installed. The cross sectional area of the entry plenum chamber (1) was greater than those of heat transfer test sections with wavy and flat walls.…”

“…Nevertheless, the further increase of cooling duty for a fin array requires the reduction of conductive and/or convective resistances. The theoretical analysis with assumption of extremely high material conductivity of fin arrays [1] revealed that the cooling performance with increased material conductivity was constrained by the available convective capability of the fin array. Convective cooling performances of fin arrays thus play important roles for this type of cooling application.…”