Field Character Of L-Shaped Constrained Flow Passage In Soft Abrasive Flow Ma-Chining And Its Active Control Method By Impinging Straeam

Different flow field characters can be induced in the L-shaped constrained flow passage when Soft Abrasive Flow Machining (SAFM) applied to structural surfaces with right angles compared with characters in passages with some other shapes. This dissertation did analysis upon field in L-shaped constrained flow passage with rec-tangular cross-section, presented an active control method of disturbing field by im-pinging stream and completed interrelated confirmatory experiment. The main con-clusions are described as follows.(1) Flow parameters which play significant rules in controlling efficiency and effect of SAFM were picked up with the help of Finnie micro-cutting theory and par-ticles motion theory. Function between turbulent parameters of abrasive phase and liquid medium was deduced to provide important theoretical basis for controlling mo-tion of abrasive by disturbing liquid phase.(2) Numerical simulation on solid-liquid flow within L-shaped passage was car-ried out with Realizable k-ε model and Mixture model, and analysis functions among various parameters were estimated by result of simulation and mathematics:gradient of liquid velocity and abrasive fraction in separating zone near wall, gradient of liquid and abrasive velocity field on typical dimension, theoretical requirement which makes exchange term in k equation of abrasive phase to be source term.(3) An active control method on turbulence parameter by impinging disturbing was proposed to meet the demand of SAFM based on theory of free shear field, the influence on some other character by the method was analyzed, and interrelated con-firmatory experiment was conducted. The experimental results show that the intro- duction of impinging stream has obvious optimization on turbulent field and some other important parameters, confirming that the method in this dissertation is feasible and effective.