Abstract
Experimental and numerical investigations are performed to provide an assessment of the transport behavior of an ultrasonic oscillatory air–water two-phase flow in a microchannel. The flow exhibits highly unsteady behavior as the water and air interact with each other during the vibration cycles, making it significantly different from the well-studied steady flow in microchannels. The computational fluid dynamics (CFD) modeling is realized by combing the turbulence Reynolds-averaged Navier–Stokes 𝑘−𝜔 model with the phase-field method in the Eulerian framework to resolve the dynamics of the two-phase flow. The numerical results are qualitatively validated by the experiment. Through parametric studies achieved by CFD simulation, we specifically examined the effects of vibration conditions (i.e., frequency and amplitude), microchannel taper angle, and wall surface contact angle (i.e., wettability) on the flow rate through the microchannel. The configuration for the highest flow rate is identified, which will help optimize the efficiency of a novel ultrasonic drying device. The described CFD modeling approach may also advance the potential applications where oscillatory or general unsteady microchannel two-phase flows may be present.