Dynamics Analysis And Experimental Study Of Soft Abrasive Flow Machining Based On SST Turbulence Model And Impinging Jet

Soft Abrasive Flow Machining (SAFM) is a new method using abrasive flow which is in turbulence state to process parts. The motion law of abrasive flow in different constrained flow passages and processing devices was analyzed based on the simulation results. Then, an improved flow passage or device was designed based on the analysis results, and the optimization processing was realized in SAFM. In this thesis, the main work accomplished includes the following.(1) According to the fact that the processing effect of the single inlet processing device was not uniform, and based on the impinging jet theory, a new method of turbulence strengthening using double inlets was proposed.(2) Based on the SST k-ωturbulence model, combining Mixture model, an analysis model for the processing of SAFM was established. The dynamics characteristic of abrasive flow in two kinds of processing device was analyzed using numerical simulation method. The results show that in single inlet processing device, there is a low value region in the center of constrained flow passages because of section break and restriction of wall on it, and there is an attenuation trend of turbulence kinetic energy along flow direction. In the whole machining process, the processing effect is not uniform on the machined surface if the distribution of the abrasive flow in constrained flow passages is stable. Due to the collision of two flows, the distribution of all parameters changed with time in double inlets processing device, and the fixed attenuation trend of turbulence kinetic energy in specific direction was broken. In a word, the double inlets processing device strengthen the random behave of the abrasive flow in constrained flow passages, and a uniform processing effect is conducted with it.(3) Machining experiments show that the surface roughness on both sides was larger than that of the center along the flow direction which processed by the single inlet processing device, and the original machining marks was removed incompletely on both sides On the contrary, the processing effect of both sides is consistent with the center of the surface along the flow direction, and the surface could reach to the mirror surface result.