Research On Structural Optimization Of Shaft Center Breather

Some research institutions at home and abroad found that performance of the shaft center breather was influenced by rotational speed, particle size and air flow rate etc. Within this research project, a study of the separation performance of shaft center breather was conducted from the perspectives of structure. The results of the study contribute to an optimized shaft center breather technology.By calculating fluid dynamics (CFD), the flow field of several modification shaft center breathers has been researched, and the oil-gas separation principle of the shaft center breather is analyzed particularly. In this paper, computational domain is simplified according to the characteristic of shaft center breather flow field in tester. RSM turbulent model is used to simulate the strongly swirling turbulent flow field of shaft center breather, and DPM model is used to simulate the particle track. Wall-film model is used to simulate the interaction of oil droplet with wall and the moving of oil film on the wall. The simulation results of two primitive structure breathers separation efficiency agree with experimental data well, it is proved that the numerical simulations result has certain reliability, and which could be used to study the breather performance affected by structure parameters.This paper also analyzes the shaft center breather velocity fields, and find that the tangential velocity profile behaves like Rankine vortex in the part of rotating wall, there are two velocity profile regions in the flow fields. Moreover, the most effective oil-gas separation region is in the free vortex. Increaseing the tangential velocity of free vortex or minishing the influence of secondary flow, will improve oil-gas separation performance of shaft center breather, through optimizing shaft center breather structure parameters. In addition, it is found that the separation of inner Cavity and ventilating pipe is linearly related to the centripetal acceleration and turbulence intensity using Regression Analysis. The results of the study contribute to an optimized shaft center breather technology.