Local Convective Heat Transfer From a Constant Heat Flux Flat Plate Cooled by Synthetic Air Jets

Abstract

The effects of a small-scale, rectangular synthetic air jet on the local convective heat transfer from a flat, heated surface were measured experimentally. The synthetic jet impinges normal to the surface and induces small-scale motions by zero-net mass flux, time-periodic entrainment, and ejection of ambient air at frequencies whose periods are far higher than the characteristic thermal time scale. The velocity field between the jet orifice and the target plate is measured in planar cross sections using particle image velocimetry and is related to the local heat transfer from the plate. The present work suggests that synthetic jets can lead to substantial enhancement of the local heat transfer from heated surfaces by strong mixing that disrupts the surface thermal boundary layer. The dependence of the local heat transfer coefficient on the primary parameters of jet motion is characterized over a range of operating conditions.

Experimental Investigation of a Synthetic Jet Array in a Laminar Channel Flow

“…• The use of a stand-alone SJ or system of synthetic jets (SJ used for intensification of heat transfer [10,11].…”

Enhancement of synthetic jets by means of an integrated valve-less pump

“…The first publication about this field in a reviewed journal was published by Trávníček and Tesař [15], although the idea had appeared before (e.g. [2], [16] and [17]). The layouts considered are similar to the well-known impinging jets: the jet generating nozzle is directed towards the cooled surface.…”

“…It should be noted that typical development strategy followed by many researchers begins at macro-size and scaled-up laboratory models, the subsequent step (which, of course, may lead to practical microfabrication problems and crucial difficulties of operation at small Reynolds numbers) being the scaling down to the final micro-size. Characteristically, early investigations of synthetic jet used macro-size actuators [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16] and [17], and only recently micro-fabrication in silicon was used by Mallinson et al [18].…”

Comparison of synthetic jet actuators based on sharp-edged and round-edged nozzles

“…The potential applications have been found especially in boundary-layer separation control [3][4][5][6][7][8][9][10], jet vectoring [11][12][13][14][15][16], heat transfer enhancement [17][18][19][20][21][22], and mixing [23][24][25]. A variant of the SJ, namely a non-zero-net-mass-flux jet (or hybrid SJ), has been investigated more recently [26-28, 21, 29-31].…”