关键词: 静态混合器, 混合特性, 数值模拟, 翼片间距, 翼片尾距

Abstract: Mixing characteristics of HEV static mixer with different tab gaps and tab wing(the distance between the last tab and the outlet)were studied experimentally and numerically.The most widely used measure for the uniformity is the coefficient of variation(CV).Smaller CV value means more uniform mixture.The volume fraction of tracer fluid was measured at the outlet,and the results were compared with standard k-ε equation,RNG k-ε equation,realizable k-ε equation,SST k-ω equation and standard k-ω equation,based on which the most suitable equation was obtained.Using this model,the CV of tracer fluid with different tab wing was studied when the tab gap was from 0.8D to 2.0D,where D is the inner dimeter of HEV static mixer. The CV of the tracer fluid at different spacing at the same benchmark section was also studied.The results showed that RNG k-ε turbulent model was in a good agreement with the experimental results with the relative error of 3.37%.It was also found that the CV decreased rapidly as the tab gap increased when tab gap≤1.7D and increased as the tab gap increased when tab gap≥1.7D.The optimum tab gap is 1.7D.The attenuation of CV was fast as tab wing increased in a certain distance,and then became comparatively slow.

Key words: static mixer, mixing characteristic, numerical simulation, tab gap, tab wing