Compact ultrasonically pulsed waterjet nozzle

A pulsed waterjet apparatus comprising:

• a water pump for generating a pressurized waterjet;
• an ultrasonic signal generator for generating an ultrasonic signal;
• and
• an ultrasonic nozzle comprising an ultrasonic transducer comprising a main body and a microtip connected to the main body for converting the ultrasonic signal into vibrations that pulse the pressurized waterjet to generate a pulsed waterjet, an exit orifice through which the pulsed waterjet exits from the ultrasonic nozzle and a water inflow inlet axially aligned with the exit orifice to convey water along a central axis of the ultrasonic nozzle via a central bore in the main body of the ultrasonic transducer, wherein the ultrasonic nozzle comprises a water bypass channel to guide the water around the microtip, and wherein the water bypass channel is an obliquely angled bore extending through the main body of the ultrasonic transducer, and wherein the ultrasonic transducer comprises a piezoelectric stack mounted on a shaft and connected to the main body such that a downstream face of the piezoelectric stack abuts an upstream face of the main body.