International Communications in Heat and Mass Transfer, cilt.141, 2023 (SCI-Expanded)
© 2023 Elsevier LtdThis research presents a simplified numerical investigation of pressure difference and vortices generation by a vertically oriented piezofan operating at different oscillating ratios and cooling effects in a vertical channel heated from side walls. The model was built by coupling the deformation overtime of a cantilever beam and the air surrounding it and the natural convection-driven air motion. Transient temperature variations and velocity distributions were analyzed for a 2D-laminar flow model in COMSOL Multiphysics software. Four piezofan oscillating ratios (OSR) of 0.15, 0.2, 0.25, and 0.3 are considered, and the results are compared against the non-piezofan natural flow condition. The cooling performance of the proposed scheme is assessed regarding the local variations in the heat flux along the heated wall of the vertical channel and the average Nusselt numbers. The results reveal that the high oscillating ratio of piezofan has a notable influence on the flow and heat transfer characteristics, and the best performance was captured at OSR = 0.3. The interaction of high momentum generated vortices with walls boundary layers makes the strong intensity vortices push left and right. Striking and sweeping the walls and streaming towards the channel exit contribute to high heat transfer effects. Compared with the non-piezofan natural laminar flow conditions, Nusselt number is increased by 28% across the entire channel in the piezofan configuration with the OSR of 0.3.