Engineers at Maxxan Systems, a computer company in San Jose, Calif. (, needed to redesign the thermal-management controls on the SG100, a two-unit high (2U), rack-mounted computer after upgrading it with two Intel 2.4-GHz Xeon processors. The previous system used a fan but reliability concerns made passive cooling a requirement. The engineers also wanted to modify the existing board design to save time and money.

To simulate and test component arrangements before building prototypes, thermal engineers built a baseline analytical model of the 2U system in Flotherm CFD software to visualize the thermal bottlenecks in the design. Results from the software and design experience produced a series of parametric analyses that led to a best design.

With 3D images of the temperatures and flow streams, the two teams quickly designed an enclosure that provided sufficient thermal dissipation and kept the product on schedule. "The 3D thermal simulation helped validate the design and let us complete the project, from concept to first working prototype, in less than a month," says Robert Vu with Maxxan.

-- Paul Dvorak