幂律流体圆管层流进口段效应的研究

Study on Entrance Region Effect of Power-law Fluid Laminar Flow in a Circular Pipe

本文首先采用方法推导了幂律流体在圆管进口段内流动的边界层动量积分方程式和能量积分方程式,并通过解能量积分方程式,求得了进口段效应诸系数及其与流动指数n之间的变化关系。以边界层内幂律流体层流速度分布假设f(η)=(1一η)^((n+1)/n)为特例,所求出的结果与文献[4]中的理论值和实验值比较表明,本文的计算是既简便又可靠的。

In this paper, from the boundary layer momentum equation, B. B. Golubef method(1) is used for deriving the momentum integral equation and the energy integral equation of power-law fluid flow in the entrance region in a circular pipe . Then the coefficients of entrance region effect and the relations between them, and the flowbehaviour index n can be obtained by solving the energy integral equation. Under the assumption of the velocity distribution within boundary layer: f (η) = 1-(1-η )n+1/n for example, compared with the theoretical and experimental data in ref. (4), the results in this paper are reliable and simple.