Experimental investigation on the jet-like acoustic streaming in front of an oscillating circular piston

Results of an experimental investigation on the sound field produced by a circular piston and the flow of air generated by the radiated acoustic wave are presented. The aim has been to create a strong jet-like wind by means of a beam of sound radiated by a powerful ultrasonic source, and to measure the speed of the airflow. The experimental data are compared with results of numerical simulations obtained by means of the finite-difference time-domain method. Two Langevin type transducers were used as the sound sources; one had a radiating surface with a diameter of 1.5 cm and the diameter of the other was 5 cm. The experimental results show that the speed of the airflow is more intense along the axis of the circular source, and that this flow extends along a larger distance for a source with a bigger diameter. The experimental data agree qualitatively well with the numerical simulations, but the obtained measurements were approximately twenty times larger than the values expected from the numerical simulations.