CFD Analyses of a Notebook Computer Thermal Management System and a Proposed Passive Cooling Alternative

A notebook computer thermal management system is analyzed using a commercial computational fluid dynamics software package (ANSYS Fluent). The active and passive paths that are used for heat dissipation are examined for different steady state operating conditions. For each case, average and hot-spot temperatures of the components are compared with the maximum allowable operating temperatures. It is observed that when low heat dissipation components are put on the same passive path, the increased heat load of the path may cause unexpected hot spot temperatures. A hard disk drive is especially susceptible to overheating and the keyboard surface may reach ergonomically undesirable temperatures. Based on the analysis results and observations, a new component arrangement considering passive paths and using the back side of the liquid crystal display screen is proposed and a simple correlation based thermal analysis of the proposed system is presented. It is demonstrated for the considered 16.1 in notebook and for a standard A4 paper sized notebook that placing the computer processing unit, the motherboard, and the memory on the lid creates enough surface area for passive cooling.