Research on Quality Control of Abrasive Flow Precision Machining Nozzles Based on Large Eddy Simulation Smagorinsky Model

In order to study the influence mechanism of the flow field distribution, formation of eddies and existence of eddies on the nozzle holes by solid-liquid two-phase abrasive flow machining, the abrasive flow machining was used to polish variable diameter nozzle and the process was calculated with the Smagorinsky sub-grid model of the large eddy simulation. The numerical simulations show that the collision and shear actions between the abrasive particles and the wall increase with the increase of fluid velocity, and the velocity of the same section has a varied velocities, which are accompanied by the existence of eddies. According to the experimental results, the surface quality of the nozzle holes after the solid-liquid two-phase abrasive flow machining is improved significantly. The value of surface roughness Ra at the large holes decreases from 1.24 μm to 0.542 μm and at the small hole decreases from 1.21 μm to 0.437 μm. The conclusions show that the solid-liquid two-phase abrasive flow machining technology may effectively improve the inner surface quality of the machined nozzle holes. There is a velocity difference in the same cross section during machining, the existence of the velocity difference is conducive to the formation of eddies. The presence of eddies is helpful to improve the shearing effect of the abrasive flow machining processes and is beneficial to obtain a high-quality surface of the nozzle holes. © 2020, China Mechanical Engineering Magazine Office. All right reserved.