FORCED CONVECTION IN MICRO-CHANNEL WITH SYNTHETIC JET: EFFECT OF OPERATING FREQUENCY

A three-dimensional computational model has been developed to investigate the cooling effect on the microchip of synthetic jet interacting with a cross-flow in a micro-channel. The conjugate problem is solved by determining the temperature distributions in a heated solid and the fluid flowing in the micro-channel which cools it, thereby simulating the application to a microchip. A parametric study was performed on a fixed geometry by using 1 MWm(-2) heat flux at the surface of the silicon wafer to investigate the effect of frequency of the jet at a constant Reynolds number, that is the amplitude is reduced in proportion to the increase in frequency. The hot region in the silicon wafer resulting from the use fluid flowing undisturbed in a micro-channel, are removed when the synthetic jet is switched on thereby significantly lowering the maximum temperature in the wafer. Contrary to the two-dimensional case, there is little difference in the cooling performance when the jet was driven at different frequencies in three-dimensional configuration. This is illustrated by the fact in the end of the simulations at a jet Reynolds number of 40, the maximum temperature in the substrate was 0.5 K lower at 1120 Hz than at 560 Hz and 1 K lower than at 280 Hz.