摘要

The present paper deals with horizontal-base pin fin heat sinks in free convection. The sinks have the same base dimensions and variable fin pitch. They are made of aluminum, and there is no contact thermal resistance between the base and the fins. The fins have square cross-sections.
The present study is both experimental and numerical. In the experiments, the heat sinks are heated using foil heaters connected to a power supply. Temperatures of the base and fins are measured by thermocouples connected to a computer-controlled data acquisition unit. In the numerical study, the sinks are modeled using the Fluent 6 software.
The fin pitch effect on the performance of the sink is assessed, and the differences between "loose" and "dense" sinks are analyzed. Also analyzed are the effects of the sink edges on the total heat transfer, and the effect of fin location in the array on the heat transfer rate from an individual fin. Comparison of experimental and numerical results is presented and discussed.
It is shown that heat transfer enhancement due to the fins increases up to a certain fin number, and then decreases, demonstrating that an optimum array exists. A relative contribution of outer and inner fin rows in the sink is assessed. In the array with edge effects the role of the outer rows is dominant. This means that the heat sink could be built without inner fins at all. However, when the edge effects are supposed to be absent, the contributions of different fins become comparable.