Experimental study of the oscillatory velocity and temperature near a heated circular cylinder in an acoustic standing wave

Experiments were performed to characterize thermo-fluid interactions between oscillatory fluid motion and the heat transferred from a hot cylinder immersed in an acoustic standing wave. A stationary circular cylinder was mounted inside a water channel and immersed in a sinusoidal oscillatory flow. Particle Image Velocimetry and Planar Laser Induced Fluorescence were used to simultaneously capture the synchronous, time-dependent velocity and temperature fields around the cylinder. The vorticity generation and heat convection from the cylinder were found to significantly differ from those in comparable steady flows. Local time-dependent, phase-dependent and total heat transfer rates were obtained as a function of acoustic Reynolds number, Keulegan–Carpenter number and dimensionless frequency parameter. The results highlight the role of secondary vortical interaction on the heat transfer.