Experimental Study on Convection Heat Transfer Enhancement of Channel-Flow with Piezoelectric Fan.

Experimental work was carried out to investigate the convection heat transfer enhancement of channel flow using a piezoelectric fan oriented along the streamwise direction. The piezoelectric fan was operated at its first natural frequency of 90.3 Hz with various excitation voltages. The average velocity of channel flow was ranged up to 3 m/s, which has the corresponding channel Reynolds number of 3,616. The experimental methodology was numerically and analytically validated. The effects of fan location on the heat transfer performance were evaluated by changing the relative position of the fan tip to the heated surface. The convection heat transfer coefficient and channel pressure drop were measured at different operational conditions of the fan and channel flow. The maximum heat transfer enhancement of 102% was achieved at a flow rate of 15 LPM when the piezoelectric fan was excited with 170 V at the front-end of the heated surface. For a fixed channel flow condition, the piezoelectric fan improved the heat transfer performance only when it was operated with amplitudes larger than the critical value. The overall heat transfer performance of the heated surface in the channel was found to be dependent on the channel flow rate and the amplitude and frequency of the piezoelectric fan. [ABSTRACT FROM AUTHOR]