Investigation on flow field of ultrasonic-assisted abrasive waterjet using CFD with discrete phase model

The characteristics of flow field have significant influence on impact erosions of containing particles in abrasive waterjet machining. However, measurement of velocity and pressure distributions in flow field is hard to implement. In present study, computational fluid dynamics (CFD) is utilized to model the abrasive waterjet flow field in ultrasonic-assisted abrasive waterjet machining with the aid of discrete phase method. The workpiece vibration is simulated by using dynamic mesh method. The effect of ultrasonic vibration on pressure and velocity distributions was investigated, as well as the particle impact parameters such as local impact angle and velocity. The results indicate that the pressure value is lower when vibration is applied on target and the lateral flow along the vibration direction is enhanced and affected the high pressurized water film. Moreover, the particle velocity is higher when vibration is introduced due to the fact that the weakening of stagnation effect owing to the shear of vibrating target surface. In addition, ultrasonic-assisted abrasive waterjet erosion experiments were conducted to explore the practical effects on material removal and erosion mechanism. The experimental results verify that application of ultrasonic vibration is considered to facilitate the material removal of abrasive waterjet.