EXPERIMENTAL AND NUMERICAL STUDY ON NATURAL AIR COOLING OF A REMOTE RADIO UNIT

With the rapid increase of heat dissipation level in modern electronic equipments, the thermal management of electronic equipments becomes increasingly important. The remote radio unit (RRU) has been widely used in the third-generation mobile communication technology, and the cooling design is important to maintain the reliability and functionality of an RRU. The heat transfer and flow characteristics of an RRU are experimentally and numerically investigated under a natural convection condition. The experimental results are in good agreement with numerical results. The effects of fin density, vapor chamber, pin-fin heat sink, and surface emissivity on the heat transfer performance of the RRU are numerically investigated. The results indicate that the optimal fin number for the RRU with the given dimensions is around 25. The vapor chamber alleviates the heat spot problem on the heat sink base and improves the average heat transfer coefficient by 16.6%. The pin-fin heat sink increases the average heat transfer coefficient by 11.2%, while it decreases the heat transfer surface area by 38.6%. The augmentation of surface emissivity slightly improves the heat transfer performance of the RRU.