An oscillating air-water interface produces a fast-speed and energy-efficient streaming jet

Steady streaming motion induced by the oscillation of an air bubble is a powerful mechanism in many applications. Recently, it is found that the dynamic oscillation of an axisymmetric air-water interface induces various streaming patterns, e.g., a low-speed streaming vortex or a fast-speed streaming jet, when the non-dimensional oscillation amplitude d/D is large (d is the oscillation amplitude and D is the diameter of the interface). In particular, the streaming jet has many extraordinary characters, such as fast speed and high energy efficiency, which can be employed in many application areas, such as in turbulent boundary layer control and microfluidics devices.