Experimental Investigation of Deflection of High-Speed Water Current with Aerial Ultrasonic Waves

Inside a simulated standing wave sound field that was formed with high intensity aerial ultrasonic waves with a frequency of 20 kHz and a rigid plate, we passed a high-speed current of water with a diameter of approximately 0.6 mm and a speed of 5–30 m/s and deflected the current using primarily the force of the field's sound radiation pressure. Together with the acoustic radiation force, acoustic streaming, produced from convergent ultrasonic waves and moving in a direction away from the rigid plate, generated a force that acted on a small object placed inside the standing wave sound field. The water current was deflected almost proportionally to the magnitude of this compound force. The current's angle of deflection depended on the electric power supplied to the sound source that produced the convergent ultrasonic waves and on the speed of the current.