Interaction of a synthetic jet with an actively cooled heat sink

In high power electronics applications, the most preferred way of thermal management is the use of a heat sink and a fan for active cooling. Though this thermal solution is fairly adequate for the current heat dissipation needs, it suffers from some serious limitations, which may tend to limit its use with time. In the present study, we quantify the limitations of a conventional fan-cooled heat sink with computational models, and propose a remedy to the problem in the form of synthetic jets. Synthetic jets are meso-scale devices operating at zero-net-mass-flux principle. These devices produce periodic jet streams, which may have velocities 10-20 times greater than the average fan velocities. As a result, positioning one or more of these jets closer to the fins can cause high velocity air currents in tightly spaced fin gaps and enhance the surface heat transfer. Results of a CFD based study have been presented. Different heat sink designs are considered, and the quantification of the observed heat transfer enhancement is provided along with the underlying flow physics. It is found that synthetic jets can enhance heat transfer in excess of 2.5 times over fan cooled tight-spaced aluminum heat sinks.