Effect of liquid properties on the stability of an abrasive waterjet

The effect of liquid properties after adding polymeric additives on the stability of an abrasive slurry (or suspension) jet (ASJ) is presented and discussed with a view to enhance the jet stability for ASJ machining. It is shown that jet disintegration is a result of the jet internal disturbances associated with the fluid properties and the external air friction acting upon the jet surface. A jet becomes more stable with the addition of polymeric additives, which is found to be mainly attributed to the increase of fluid viscosity. By contrast, the surrounding air friction with the jet results in the jet to disintegrate, and this external effect increases with an increase in the jet velocity. Based on the findings of the experimental investigation, a parametric model is then developed using a dimensional analysis approach to predict the jet compact length, i.e. the length of the jet stable region. The developed model is finally verified experimentally, which shows that the model predictions are in good agreement with the experimental data.