A system level thermal analysis is performed by employing the computational fluid dynamics (CFD) method on a large telecommunication rack. Each rack consists of two identical shelves located on the top-to-bottom orientation. Each shelf includes one fan tray with 6 fans, 3 card cages with a total of 50 printed circuit boards (PCBs). Air enters from the front of the shelf, and then makes a 90-degree turn upwards through PCBs, and finally turns another 90-degree to exit the system from the back of the shelf. The system level analysis is performed independently on each shelf. The main purpose of the analysis is to determine the air flow rate to individual printed circuit boards as well as the air temperature distribution in the system. The computed flow rate for individual PCBs is then used for a detailed board analysis to predict the component temperatures of individual boards.

This content is only available via PDF.
You do not currently have access to this content.