Heat transfer characteristics of piston-driven synthetic jet

Abstract

This paper deals with numerical and experimental investigations on the heat transfer characteristics of a synthetic jet driven by a piston actuator. An experimental setup was designed and fabricated. Numerical studies were conducted using the finite volume-based commercial software ANSYS Fluent. The target surface is a copper plate with a heater placed underneath. Air is considered as a cooling medium. Effects of frequency of jet, the dimensionless distance between the orifice and target plate(Z/D), Reynolds number, orifice diameter and the number of orifices on the heat transfer characteristics are presented. Numerical results are in fair agreement with experimental results. The results indicate that the Z/D and jet frequency have a substantial impact on the heat transfer rate. In the frequency range considered the optimum value of Z/D is 8. It is found that with the increase of frequency, the average Nusselt number increases. For circular orifice and at high Z/D, the orifice diameter should be smaller for better heat transfer. When compared to single jet multiple jets have a higher heat transfer rate. Maximum and minimum values of normalized pressures (Pnr) are achieved for high actuation frequency and smaller areas of the orifice.