THE EFFECTS OF A CROSS-FLOW SYNTHETIC JET ON SINGLE-PHASE MICROCHANNEL HEAT TRANSFER

Abstract

The present study is an experimental investigation of a novel hybrid cooling scheme which combines a microchannel heat sink with a synthetic jet actuator. The heat sink consists of a single rectangular microchannel with dimensions of 550 μm in width, 500 μm in depth, and 26 mm in length. The synthetic jet actuator with a 100-μm-diameter orifice is placed vertically above the microchannel and 5 mm downstream from the channel inlet. The microjet is synthesized from the fluid flowing through the microchannel. Periodic disturbance is generated when the synthetic jet interacts with the channel flow. Heat transfer performance is enhanced as local turbulence is generated and propagated downstream of the channel. The scale and frequency of the disturbance can be controlled by changing the driving voltage or frequency of the piezoelectric driven synthetic jet actuator. The effects of a synthetic jet on microchannel heat transfer performance were evaluated as a function of the microchannel flow rate, the jet operating voltage, and frequency, respectively. Approximately 40%−50% heat transfer enhancement are achieved for some test cases. The pressure drop across the microchannel increases slightly with the synthetic jet. This study concludes that the synthetic jet can effectively enhance single-phase microchannel heat transfer performance.