Case Study of Thermal Management for Mobile Multi-Media (MMM) Applications

Mobile Multi-Media (MMM) is a term used in the automotive industry to describe the growing use of consumer electronics, satellite-based navigation systems and Internet applications in the automobile. As an example of the thermal challenges that confront the use of such systems in the automotive environment, the mounting of a digital video disc (DVD) player on the roof of an automobile is considered in this paper. Of particular interest is the cooling of the optics region of the DVD player, which is critical to the operation of the mechanism. FLOTHERM simulations guide the design of the enclosure surrounding the mechanism, and extensive experimental studies help corroborate the results of the analysis. The application involves the use of a fan, which helps cool all interior devices including heat-sink mounted regulators and the DVD player. Despite venting the enclosure to channel air flow, analysis reveals that it is necessary to reduce heat dissipated inside the box to meet stringent boundary conditions. Discussions on the effect of solar heating of the roof and high voltage are also presented. Employing a hybrid approach of electrical reduction in power dissipation and mechanical reduction in thermal resistance, temperatures in the DVD enclosure are reduced to an acceptable level.