Cooling of telecom systems-thermal optimization using CFD methods

Telecom systems incorporate electronic equipment which may use several kilowatts of electric power. Even if it were possible to maximise the efficiency of the power supplies to 100%, the challenge for the thermal management keeps on getting stronger, because almost all of the electric power is converted into beat which has to be removed from the components, the modules and from the enclosure. In order to provide best reliability and availability, it is vital to have thermally optimized building blocks such as power supply modules and of course to have the full rack cooling control through optimised flow. With the increasing power density the optimized thermal management becomes a task for numerical methods and simulation applications. This paper shows the embedded use of computational fluid dynamics for the thermal optimisation process of a telecom power supply module, extending the solution domain to the full 19" rack enclosure. Especially in rack-systems, the cooling requirements for the modules are influenced by thermal interaction between them. To be able to control the temperature and flow distribution inside racks, a good knowledge of the dominating physical effects is necessary for all levels of detail.