幂律流体同心环空螺旋流数值模拟

环空螺旋流是钻井液在钻井作业中常见的一种流型，怎样方便、快速及高精度地计算其流速场与压力梯度是一个重要工程问题。提出直接利用线性化迭代法求解幂律流体在环空中螺旋流的流场及压力梯度，避免了求解非线性方程组而可能出现迭代发散的问题，该线性化迭代算法真实可信，精确度高。使用线性化迭代算法，仅以求解两个三对角线性方程组为一次循环，运算速度快，占用时间少，精度高，收敛性得到可靠保证，是矿场使用的好方法，为矿场作业中水力参数设计提供了科学依据。

Numerical modeling of the power-law fluid in a helical flow

Helical flow in the annular is a common flow pattern in drilling, and it is an important engineering problem for fast and accurate calculating of the flow field and pressure gradient. It is proposed that by using the linear iteration method, the flow field and pressure gradient of power-law fluid in the helical flow can be worked out, and this method avoids the problem of iteration defocusing, and it is more reliable and accurate. This method is also simple and fast, and suitable for using on site.