Numerical and experimental study on the flow characteristics of abrasive slurry jet with polymer additives

Abstract

Based on a refined mathematical model, the hydrodynamics of abrasive slurry jet (ASJ) was numerically investigated in consideration of the non-Newtonian rheological properties of the slurry. It is found that adding polymer has significant effects on the jet properties, such as axial velocity and abrasive volume fraction. The coherence length (L c) is proposed to measure the initial region of jet, where external air acts insignificantly on the axial velocity magnitude and thus the averaged kinetic energy is large. In the ASJ flow field, L c is increased after adding polymer additives, while reduced as the operating pressure (P 0) goes up. The prediction to the L c agrees well with the experimental results, with P 0 ranging from 1 to 16 MPa. Accordingly, an empirical formula is presented to describe the relationship between L c and P 0. The distinct characteristics of ASJ with polymer additives together with the verified length model of coherence region provides a qualitative and quantitative basis for the optimization of ASJ machining process, for instance, improving cutting efficiency and precision.