Abstract:

The existing eulerian and arbitrary lagrange eulerian (ALE) grid-based algorithms were limited to study the hydrodynamic characteristics of pre-mixed abrasive waterjet (AWJ) in a cutting head. Smooth particle hydrodynamics (SPH) coupled finite element method (FEM) algorithm was adopted to establish a new AWJ model, by which the abrasive particle could enter into the mixing chamber in a low velocity and chould be accelerated in the focus tube by a high-speed waterjet from the orifice. SPH particles were used to model the high-speed waterjet and the FEM was applied to model the discrete abrasive particle, cutting head and workpiece. Consequently, the evolution of abrasive and waterjet velocities along focus tube was analyzed and the trajectory of single abrasive particle in focus tube was sighted. The relationships between abrasive particle velocities and different water pressures were studied and the rule of outlet velocities of abrasive particle vs. dimensionless ratio of diameter were conducted. The penetration depth caused by single abrasive particle impact was obtained. This model was validated by the existing theoretical and experimental data.

Key words: abrasive mixing-and-acceleration, SPH coupled FEM, AWJ cutting, penetration depth