Heat transfer characterization of air circulation inside a system of stackable electronic devices

Abstract

The purpose of this study is to investigate the ability of forced circulated air inside a system of stackable electronic devices in transferring heat generated from four identical Intel J1900 10W computer processor unit (CPU). Each CPU was isolated from each other by locating it inside four separated electronic devices which are stacked on each other and sandwiched between cool air supply chamber at bottom and exhaust chamber at top. Validation of numerical model against a benchmark forced convection problem was performed and compared results are in good agreement. Effect of viscous heating, buoyancy, cooling fan speed and device stacking level were numerically analyzed by commercially available computational fluid dynamics (CFD) software ANSYS Fluent version 16. Navier-Stokes equations were solved in simulation of conjugate heat transfer where conduction occurs from CPUs into heatsink and mini-ITX motherboard and subsequently via forced convection of circulated air into environment. Results show that cooling fan speed of 1.0 m/s for prevention of CPU failure during operation is the minimum allowable speed and selected enclosure material should be able to withstand at least 76 °C of near wall temperature.