Natural convection enhancement of channel array in conjunction with wall surface

Despite the active air cooling with micro-fan is effective and commonly used, passive cooling enhancement is rather getting important for consumer electronics thermal management. As active air cooling may produce acoustic noise during its operation, the natural convection enhancement can be helpful for the noise reduction by decreasing required active cooling performance. In this report, an approach of dissipating heat through the enclosure wall to the ambient with using channel array built in the wall is proposed and investigated. The inside wall is assumed to contact to isothermal spreader, which spreads the heat from the device. Vertically oriented channels in the composite wall are utilized instead of flat solid wall and are served as mechanical structure as well. The study is focused on typical high dense packaging design of consumer digital electronics as like home-use bookshelf computers. Since the airflow space is limited in the equipment, passive cooling needs to be maximized with spreading the heat generated from the device. Although, passive cooling from skin wall is limited since the maximum allowable temperature must be managed in harmless range for the case user touches the enclosure. The channel structure installed in the wall is found to effectively help the passive cooling with higher channel temperature with maintaining external skin temperature in proper range. Such channel composite wall has a benefit on its flat surface. It does not impact on cosmetic design but fin surface enhancement does impact. The channel gap is limited for space efficient design requirement as well. In such limited range of the composite wall thickness, the effectiveness is demonstrated by analytic model correlated with numerical analysis comparing with single solid isothermal wall. For the typical thermal conditions, the enhancement is found several times effective compare to the single solid wall while the channel composite wall is properly designed.