Modelling of abrasive particle energy in water jet machining

•Validation of a phenomenological model of the abrasive water jet cutting head.•Goal is to predict the energy of abrasive particles leaving the focussing tube.•Size distribution of abrasive particles is shown to be indispensable.•Abrasive breakage has a significant impact on the energy transfer process.•Validation for a large set of experiments; model correlation of 98% obtained. A phenomenological model of the three-phase flow inside an abrasive water jet machining cutting head has been developed. Several improvements over previously presented models such as taking into account the abrasive particle size distribution, and the effect of breakage of particles on the energy flux have been made. The model has been validated using an extensive set of experimental data with wide variations in cutting-head geometry, operating pressure, and abrasive mass flow rates. The cross-sectional averaged abrasive particle velocity at the exit of the focussing tube has been predicted with good accuracy over the whole range of experiments. In particular, the Pearson correlation between the model and the experimental results is found to be more than 95%, implying the utility of this model in design.