An improved soft abrasive flow finishing method based on fluid collision theory

Soft abrasive flow (SAF) finishing has advantages in precise processing for the workpieces with tiny scale or irregular geometric surfaces. However, current SAF finishing methods have surface quality problem caused by uneven flow field profile. To resolve the problem, a novel double-inlet SAF finishing method is proposed based on the fluid collision theory. Taking two constrained processing apparatuses (single-inlet and double-inlet) as the objectives, in combination with the shear stress transport (SST) k-omega turbulence model, the fluid mechanic models for the two apparatuses are set up, and the preliminary abrasive flow field characteristics are acquired. Referring to the collision conservation principles, the profiles of dynamical pressure and turbulence intensity in double-inlet constrained passage are obtained. The simulated results show that the flow field distribution of single-inlet passage is in a steady state and non-uniform, a periodic oscillation phenomenon appears in double-inlet passage, and it can enhance the turbulence intensity and movement randomness of abrasive flow. The processing experiments show that the proposed SAF finishing method can make the roughness on parallel flowing direction less than 50 nm and can improve the finishing uniformity and efficiency.