Ultrasonically generated cavitating or interrupted jet

An ultrasonic nozzle for generating a fluid jet having enhanced erosive capability, comprising:

• a nozzle body having a fluid flow channel formed axially therethrough with an inlet at an upstream end thereof for receiving a pressurized fluid and an orifice at a downstream end thereof for discharging said pressurized fluid towards a surface to be eroded, said orifice comprising at least two nozzles for directing said pressurized fluid flowing therethrough towards one another in a converging stream whereby the velocity of the fluid following convergence exceeds the velocity of said fluid prior to convergence;
• transformer means axially aligned within said flow channel to form in cooperation with said flow channel an annulus therebetween for the flow of said pressurized fluid;
• and
• vibratory means for ultrasonically oscillating said transformer means to pulse said pressurized fluid prior to the discharge thereof through said orifice;
• wherein said flow channel and said transformer means taper conformably axially inwardly in the direction of flow of said pressurized fluid.

A method of eroding the surface of a solid material with a high velocity jet of fluid comprising the steps of:

• directing pressurized fluid through an annulus in a nozzle formed between a fluid flow channel in said nozzle and an ultrasonic transformer axially aligned within said channel;
• discharging said fluid through an orifice at a downstream end of said fluid flow channel in a stream comprising an outer annular jet of high velocity laminar flow fluid surrounding a zone of lower pressure turbulent flow fluid;
• oscillating said transformer at an ultrasonic frequency to pulse said lower pressure fluid axially downstream of said transformer prior to the discharge thereof through said orifice;
• focusing the energy of said transformer immediately downstream thereof in said zone of lower pressure turbulent flow to increase the erosive power of said fluid discharged through said orifice.

An ultrasonic nozzle for generation of a high speed fluid jet having enhanced erosive capability, comprising:

• a nozzle body having a fluid flow channel formed axially therethrough with an inlet at an upstream end thereof for receiving a pressurized fluid and an orifice at a downstream end thereof for discharging said pressurized fluid towards a surface to be eroded;
• transformer means axially aligned within said flow channel to form in cooperation with said flow channel an annulus therebetween for the flow of said pressurized fluid;
• and
• vibratory means for ultrasonically oscillating said transformer means to pulse said pressurized fluid prior to the discharge thereof through said orifice;
• wherein said flow channel and said transformer means taper conformably axially inwardly in the direction of flow of said pressurized fluid at a uniform rate such that the transverse width of said annulus remains constant along the length of said transformer means.