螺旋管道内幂律流体流动数值模拟

Numerical simulation on power-law fluid flow in helical pipes with circular cross-section

螺旋管道可作为聚合物溶液的分层配注器。根据螺旋管道内聚合物溶液的流动特征,建立了正交螺旋坐标系下Navier-Stokes方程。通过无因次分析,得到了螺旋管道内充分发展幂律流体流动的控制方程组。采用有限容积法,研究了圆截面螺旋管道内幂律流体的流动规律;采用三角形网格进行了数值计算。讨论了曲率和挠度对二次流动、流函数等值线和轴向速度的影响,研究了不同曲率和挠度螺旋管道内流量与压力梯度之间的关系。在相同流量下,螺旋管挠度和曲率越大,压力梯度越大;挠度和曲率相同的螺旋管流量越大,压力梯度越大。

The helical pipe can be taken as multi-zone flow regulator of polymer injection. The Navier-Strokes equations for the orthogonal and helical coordinate system were established according to the features of polymer solution flow in helical pipes. The governing equations for fully developed flow of power-law fluid in helical pipes were obtained by using dimensionless analysis method. The power-law fluid flow in helical pipes with circular sections was studied by using finite volume method. The triangle mesh was applied to numerical calculation. The effects of curvature and torsion on secondary flow, isoline of stream function and distribution of the axial velocity of flow were discussed. Numerical calculation shows that the pressure gradient increases with the increment of flow flux for the helical pipes with the same curvature and torsion, and the pressure gradient increase with the increment of curvature and torsion for the helical pipes with the same flow flux.