Enhancement of heat transfer in a synthetic jet actuated by piston cylinder

Arun Jacob,Ka Shafi,Ke Reby Roy

doi:10.1177/16878140211049139

Abstract

Modern electronics demand more powerful cooling systems due to an increase in heat dissipation. The traditional cooling techniques reached their limit and the synthetic jet impingement arises as a promising method for cooling of modern electronic systems. This paper presents the experimental studies on the heat transfer characteristics of a synthetic jet. The synthetic jet is driven by a piston actuator. The effects of dimensionless parameters like the distance between the orifice and heater plate (Z/D), the ratio of stroke length to diameter of orifice ( L/D), Stokes number, and Reynolds number are discussed. The effect of orifice geometry, number of orifices are also presented. The results indicate that the Z/D and Stokes number have a significant influence on the heat transfer rate. As the Stokes number increases the heat transfer increases due to an increase in axial momentum and turbulence in the flow direction. For circular orifice and at high Z/D, the L/D ratio should be higher for better heat transfer. Rectangular orifice performs better than square and circular geometries. When compared to single jet multiple jets have a higher heat transfer rate. Maximum and minimum values of normalized pressure ( Pnr) are achieved for high Stokes number and smaller areas of the orifice.

Highlights

In the fast-growing technology, the demand for compact and high-speed electronic devices has increased dramatically
Experiments were conducted on a constant heat flux surface to evaluate the performance of a synthetic jet powered by a piston cylinder arrangement
The axial momentum and turbulences in the flow direction increases as the Stokes number is increased

Summary

Introduction

In the fast-growing technology, the demand for compact and high-speed electronic devices has increased dramatically. Lee et al.[7] carried out an experimental study to identify the influence of nozzle diameter on heat transfer and fluid flow characteristics of synthetic jet. Dahalan et al.[17] compared different orifice shapes and diameters on the heat transfer characteristics of synthetic jet They concluded that the smaller circular orifice produces higher maximum pulse jet velocity. Mangate et al.[21] experimentally investigated the heat transfer characteristics of multiple orifices with different shapes such as circular, diamond, and oval at different stokes number, pitch ratio, and Z/D ratios. A small change in any parameters may affect its performance In this experimental study, the heat transfer and flow characteristics of a synthetic jet actuated by a piston-cylinder arrangement are presented.

Experimental procedure

Result and discussions

Findings

Conclusions