摘要
为精确估计抽油杆波动方程中的粘性阻尼系数,提出基于等摩擦功原理的等效粘性阻尼系数计算方法。该方法通过建立管杆同心环空牛顿流体层流的运动方程,结合抽油杆上、下冲程的边界条件,求解了上、下冲程不同的环空流场分布及对应的粘性能耗。根据VALEEV和REPIN的流体与接箍摩擦力公式,推导了上、下冲程的接箍局部阻力损失。由1个周期内波动方程粘性阻尼项所做功等于抽油杆和接箍的能耗,得到了等效粘性阻尼系数。计算算例中,张琪阻尼公式计算值比提出的等效阻尼系数小15.0%,接箍阻尼能耗占总阻尼能耗的19.0%。研究结果为更准确预测抽油杆粘性阻尼提供了理论依据。
In order to improve the estimation accuracy of viscous damping coefficient of sucker rod sting＇s wave equation,a method of determining viscous damping coefficient based on equal friction loss has been proposed. By establishing motion equation of laminar Newtonian flow in tubing-rod annular and together with boundary conditions of up and down strokes of suck rod,the flow velocity distribution and corresponding viscous dissipation were obtained. The local friction loss of coupling was deduced according to friction force formula proposed by Valeev and Repin. The equivalent viscous damping coefficient was derived when energy loss of sucker rod and coupling is equal with work by viscous force in wave equation during one stroke. Calculation case shows the proposed method gives a coefficient 15. 0% higher than that of Zhang Qi＇s method. The energy loss of couplings accounts 19. 0% of total energy loss. The study provides a theoretical basis for more accurate prediction of the viscous damping of sucker rod.
出处
《石油机械》
2016年第6期83-87,共5页
China Petroleum Machinery
基金
国家自然科学基金创新研究群体科学基金项目"机电液系统基础研究"(51221004)
关键词
抽油杆
波动方程
阻尼系数
粘性耗散
等摩擦功
sucker rod
wave equation
damping coefficient
viscous dissipation
equal friction loss
