Axial Propagation Property of Oscillation in Water Jets.

In the field of water jet technology the improvement of cutting efficiency has been recognized as one of the most important research targets. To solve this problem an oscillating jet nozzle was developed. In this nozzle several piezo-electric transducers are attached to a vibration plate, and through this plate oscillation of piezoelectric transducers is propagated to inner high pressure water, then oscillating jets emanate from a nozzle outlet.To optimize the efficiency of the oscillating jet nozzle an appropriate frequency must be selected undergiven water jet velocity and jet diameter.In this paper the authors examine this problem from the point of hydrodynamic stability of oscillating jets. Firstly the diagram for selecting the optimum oscillation frequency is presented. Then experimental results are compared with theoretical results which were predicted by the hydrodynamic stability theory. Both results show qualitative agreement.