Effects of piezoelectric fan on cooling flat plate in quiescent air.

A test facility was built to investigate the cooling effects of a piezoelectric fan on a heated flat plate in a quiescent atmosphere. The facility consists of a heat source of a thin Ni-Cr foil and a piezoelectric fan for cooling the foil, where the surface temperature on the foil was measured by an IR camera. 3D unsteady numerical simulations were then conducted to analyze the relationship between the jet flow from the piezoelectric fan and the temperature distribution on the heated plate. The measured temperature data was used for validation of the numerical results. Without the fan, the temperature is highest at the center of the plate and lowers toward the plate edge. With the operation of the fan, the temperature at the center of the plate is locally reduced by 28 °C. Based on the experiments and simulations, it is confirmed that the piezoelectric fan is very effective to cool the plate locally. In addition, it was found that the local convective heat transfer coefficient is closely related to the movement of the vortices generated by the fan. • Cooling effects of a piezoelectric fan are analyzed by experiments and simulations. • The piezoelectric fan is very effective to cool the heated surface locally. • The local heat transfer is significantly enhanced by the vortices form the fan tip. • The flow changes quickly but the surface temperature keeps the same during a cycle. [ABSTRACT FROM AUTHOR]