CFD modelling of electronic components becomes increasingly more important as CFD spreads into the design process. This paper compares the results of a detailed CFD model of a heat sink with experimental data. Then a technique for representing the heat sink in a coarse manner in a CFD model is presented and compared with the detailed CFD model. Agreement is quite good, indicating that this technique can be used when representing heat sinks in larger card or system models. >

Coarse and detailed CFD modelling of a finned heat sink

An Experimental Assessment of Numerical Predictive Accuracy for Electronic Component Heat Transfer in Forced Convection—Part I: Experimental Methods and Numerical Modeling

A Computational Fluid Dynamics (CFD) tool is used to evaluate the velocity and the temperature fields of air flow in a computer system enclosure. Simulations focused on the six printed circuit board regions where approximately 37 W of power was generated on the component side of the board. Three-dimensional, steady-state, turbulent air flow is assumed. Solutions include pressure, velocities, and temperature. Both straight and swirl flow cases at fans were considered. The actual air flow rate at fans was determined by matching the predicted pressure rise across the fan to the given fan characteristics. Experiments were performed under real life conditions. The actual computer chassis was tested inside a temperature-controlled chamber. Air temperatures between two printed circuit boards were measured in various positions and compared with the simulations. Results demonstrate a reasonable agreement between the temperatures obtained by simulations and measurements. In all comparisons, average errors were less than 10%. The introduction of swirl at fans made no significant effect on temperatures. A hot spot appeared in the inner side of the air passage between boards; this hot spot was created due to the recirculation of low velocity air. Some recommendations on improvements of the simulation are also presented. >

Application of a CFD tool for system-level thermal simulation

A computational fluid dynamics (CFD) tool is used to evaluate the velocity and the temperature fields of air flow in a computer system enclosure. Simulations focused on the six printed circuit board regions, where approximately 37 W of power was generated on the component side of the board. Three-dimensional, steady-state, turbulent air flow is assumed. The actual air flow rate at fans was determined by matching the predicted pressure rise across the fan to the given fan characteristics. Both straight and swirl flow cases at fans were considered. Experiments were performed under actual life conditions to verify the computational data. Results demonstrate a reasonable agreement between the temperatures obtained by simulations and measurements

This paper uses CFD (Icepak) to identify a cooling solution for a desktop computer, which uses an 80 W CPU. The design is based on a total chassis power dissipation of 313 W (40 W PCI cards). This represents significant power dissipation for the chassis components (memory, chipset, AGP and PCI cards, and peripherals). The analysis is also extended to 100 W PCI power. Of key interest is minimization of the chassis air flow requirements. The design is able to cool the chassis with one case fan and the power supply fan. A ducted 80/spl times/60 mm CPU heat sink is able to meet the CPU temperature specification. System level design improvements were made to provide better cooling for AGP and PCI cards.

Ronald L. Linton

Papers

Coarse and detailed CFD modelling of a finned heat sink

Thermal model of a PC

Thermal Model of a PC

Benchmark problems for system-level electronics cooling

Solution of a system-level benchmark problem in electronics cooling