聚合物流体入口收敛流动的数值模拟

Numerical Simulation for Entrance Converging Flow of Non-Newtonian Fluids

聚合物流体从大截面流道进入小截面流道时产生的入口收敛流动,是工业中常见的流型之一。基于聚合物流体入口收敛边界流线方程,应用MATLAB对入口收敛流动进行了数值模拟,讨论了Bagley校正因子(e)、非牛顿指数(n)、流道收缩比(λ)等因素对入口收敛流线和入口自然收敛半角(α0)的影响。结果表明:在一定的条件下,入口收敛边界流线的半径r随着e的增加而增大,但随着n的增加而减小,而λ对入口流型的影响不明显;另外α0随着e的增加而减小,但随着n的增加而增大,α0与λ之间呈非线性关系。模拟结果与实验观测较为接近。

An entrance converging flow will be produced when a non-Newtonian fluid enters a small channel from a big one, it is one of common flow patterns in industry. Based on a boundary stream-line equation of a non-Newtonian fluid in entrance converging flow, a numerical simulation for the entrance converging flow was made by using MATLAB, and the influences of Bagley correction factor （e）, non-Newtonian index （n） and channel contraction ratio （λ） on the enter converging boundary stream-line and enter natural half angle （α 0） were discussed. The results showed that the curvature of the enter converging boundary stream-line increases with an increase of λ, while decreases with an addition of n, and the effect of on the enter flow pattern was insignificant; Oreduces with an increase of e, while increases with an addition of n, and a relationship between α 0 and λ was nonlinear under given conditions. The simulation results were close to the experimental results.