Experimental Heat Transfer Enhancement for Single Phase Liquid Micro-Channel Cooling Using a Micro-Synthetic Jet Actuator

Abstract

The present work experimentally investigates the thermal effects of a synthetic jet actuator on the heat transfer performance of single-phase flow confined in a microchannel heat sink. The heat sink consisted of a single rectangular microchannel 500 μm wide, 300 μm deep and 26 mm long. Deionized water was employed as the cooling fluid. A synthetic jet actuator with a 100 μm diameter orifice was placed right above the microchannel and 5 mm downstream from the channel inlet. A Unimorph piezoelectric disc bender was employed as the synthetic jet actuator. The effects of the bulk microchannel flow Reynolds number, the synthetic jet operating voltage and frequency on the microchannel heat transfer performance are being investigated. The Reynolds number ranges from 100 to 500. The actuator driving voltage and frequency ranges in 20–180Vp-p and 10–150 Hz respectively. The results from the case without synthetic jet are compared to those with synthetic jet. It shows that the thermal effects of the synthetic jet are functions of the jet driving voltage, frequency, as well as the bulk mass flow rate in the microchannel. For the case of Reynolds number equal 177, around 24% enhancement is achieved under specified jet operating conditions for a single synthetic jet.