关键词: 非牛顿流体, 偏心, 环形空间, 螺旋流, 速度分布

Abstract: The governing equations of the helical flow of non-Newtonian fluid in eccentric annuli are theoretically established.They are the 4th order nonlinear nonhomogeneous partial differential equations with variable coefficients expressed by the stream function and axial velocity in the bipolar coordinate system.The calculation steps of the finite difference method of these equations are given.Given the examples of experimental data of water and CMC aqueous sol ution from laboratory,the velocity distribution functions of the helical flow of non-Newtonian fluid in eccentric annuli are calculated and analyzed.The results show that there is a secondary flow involved in the helical flow of the non-Newtonian fluid in eccentric annuli,and that the eccentricity is a major factor to exert influences on the size of the region of secondary flow.

Key words: non-Newtonian fluid, eccentricity, annulus, helical flow, velocity distribution