Analysis of Airflow Diversion in a System of Integrated Electrical Components

The task of system-level thermal management in electrical systems has never been simple and has only become more difficult in recent years as industry pushes toward devices with higher power densities. A common practice in many power electronic devices is to use an aluminum heat sink along with at least one cooling fan. This paper presents a parametric study that was performed on a DC-DC power converter to determine the thermal response of heat dissipating components when the incoming cool air is diverted. The scenarios that are investigated include diverting the air to flow only over the top of the heat sink and diverting the air to flow only over the top of the heat sink and diverting the air to flow only through the heat sink. The analysis performed in this paper was done so using IDEAS, a three-dimensional finite element analysis (FEA) program that allows the user to simulate the affects of conduction and convection heat transfer in a forced-air cooling environment. To divert the incoming air, a plate was inserted into the model between the heat sink and the two inlet fans such that the fans were partitioned into four sections. The amount of air that each fan section produced was governed, thus diverting the air to flow in pre-specified areas. The study looked at six scenarios, each with its own unique volumetric flow setting. The scenario that involved diverting all of the air to flow through the fins of the heat sink proved to cause the lowest system-wide temperatures. This best-case scenario reduced the maximum system temperature by nearly 50% from the worst-case scenario.