Nonuniform air flow and cooling in rack systems -prediction by Computational Fluid Dynamics

The power density as well as the absolute power consumption in telecommunication equipment keep on increasing continuously. In new generation platforms like ATCA (advanced telecommunications computing architecture) up to 16 boards with up to 300 W heat dissipation each can be used in a 19" rack. A typical cooling for such an equipment uses fan trays with the fans forcing the air flow through the gaps between the boards. Unfortunately the fans do not provide a uniform flow pattern, so the cooling effect and also the temperatures will also be non-uniform. This paper shows how CFD (computational fluid dynamics) can be used for the prediction of flow and temperature distribution and how the cooling can be optimized.