To calculate discharge port pressure, this article considers the influence on frictional pressure drop in the gas and liquid two-phase flow between rod and tubing owing to rotation of rods.
在计算排出口压力计算过程中，考虑了由于抽油杆柱旋转引起杆管环空气液两相流摩阻的影响。
2
The additional frictional pressure drop for vertical tubes due to its connection with the bend was accounted into the frictional component due to return flow.
回弯压力降除考虑回弯头的局部阻力外，还包括相连直管段受回弯影响而增加的压力降。
3
With oil, gas, water as working fluids, the experiment studies of frictional pressure drop characteristics of oil gas, gas water two phase flow in vertical helically coiled tubes were carried out.