Review: Synthetic Jets and their Cooling Applications

Abstract

The objective of this paper is to present a review of the state of the art in cooling applications of synthetic jets. Cooling by means of synthetic jets represent an alternative technique to liquid cooling, in which air is still the working fluid. To this end, it is necessary first to present the varying types of synthetic jet generators, the fluid dynamic characteristics and the dimensionless performance parameters of the jets themselves. Synthetic jets are produced in generators that consist of a sealed cavity containing a small orifice. A boundary oscillation induces fluid movement in and out of the cavity through the orifice that, in the region external to the orifice, develops into a synthetic jet. The synthetic jet has average velocity properties similar to a steady jet albeit with a higher level of turbulence due to its oscillatory nature. Cooling applications of synthetic jets can occur in an impacting or tangential configuration. Regardless of the configuration used, several experimental and numerical studies have demonstrated that there is a significant increase in heat transfer compared to natural convection and forced convection with steady state turbulent flows.

Keywords: synthetic jets, cooling, forced convection