偏心环空中非牛顿流体轴向层流的数值分析

讨论了充分发展的无弹、剪切变稀幂律流体在偏心环空管中的轴向流动。幂律流体的本构方程是许多工业过程中流体的流变特性参数模型。数值分析时通过坐标变换将过流截面变换成单位圆，并采用有二次精度的差分法将控制方程离散化。文中给出了环空半径比(0.2≤r^*≤0.8)、偏心率(0≤e^*≤0.8)和流体流性指数（0.2≤n≤1）在很宽范围内变化时的数值解。对数值解的分析表明流性指数和偏心率对流动状态都有很强的影响。就偏心率而言，它使流场在环空最窄处速度停滞而在最宽处出现最大值，并在不同的角度处速度场不同。还将研究结果与近期国内外幂律流体的数值模拟研究结果进行了比较分析。

Numerical analysis of laminar viscous non-Newtonian liquid axial flows in eccentric annuli

Laminar fully developed flows of an inelastic shear-thinning power-law fluid through an eccentric annulus are considered. The fluid rheology is modeled by the power-law constitutive equation, which is representative of many industrial process liquids. The flow cross-section geometry is mapped into a unit circle by means of a coordinate transformation, and the governing momentum equation is solved by finite-difference techniques using second-order accurate discretization. Numerical solutions for a wide variation of annuli radius ratio(0.2≤r*≤0.8), pipe eccentricity(0≤e*≤0.8), and shear index(0.2≤n≤1) are presented. Both fluid rheology and annuli eccentricity have a strong influence on flow behavior. The eccentricity causes the flow to stagnate in the narrow gap with higher peak velocities in wide gap, and large azimuthal variations in the velocity field. Comparisons are made with the results of other recent numerical studies.