Abstract: To solve the problem of unable to calculate particle velocity of high concentrate solid-liquid two-phase flow when impacting wall, a model which simulates particle movement locus in boundary layer is proposed. Based on results simulated by mixture model and realizable k-ε model, velocity and angle of incidence can be calculated through analyzing particle velocity before incidence, calculating boundary layer thickness, establishing velocity field in boundary layer and solving particle motion function. Distribution of dynamic pressure and volume fraction of abrasive on the workpiece’s surface is analyzed associated with two kinds of flow passage with different restrained components. Experimental results are analyzed to get design law for restrained component. Research results indicate that machining is directly affected by incidence velocity of abrasive, volume fraction of abrasive and dynamic pressure on surface of workpiece, which are positive correlation with material removal rate. Initial degree of roughness should be below 0.2 μm employing machining parameters. Initial machining track should be checked before design restrained component beside consider characteristic of flow field.

Key words: Boundary layer, Particle motion, Restrained component, Softness abrasive flow machining, Solid-liquid two-phase flow