连续油管螺旋段摩阻压耗数值模拟

根据流体力学理论,以连续性方程和N-S方程为控制方程,对连续油管螺旋段牛顿流体流动进行数值模拟,研究螺旋段的流动特性及其摩阻压耗的变化规律,在此基础上以迪恩数和曲率为自变量、考虑曲率和管路的几何尺寸对摩阻系数的影响,建立一套针对牛顿流体预测螺旋段摩阻系数的回归公式,并与精选的几个适用性较强的预测公式进行对比。结果表明:由于二次流的存在,螺旋段的流动压耗较一般直管段大,且不能忽略;回归公式在层流和紊流区预测结果与适用性较强的公式结果具有很好的一致性,验证了用数值模拟方法研究螺旋段的可行性。所提出的螺旋段摩阻压耗预测公式可为连续油管流体力学研究提供方法和理论上的支持。

Numerical simulation on friction pressure loss in helical coiled tubing

According to hydrodynamic theory,based on continuity equation and N-S equation,the numerical simulation for Newtonian fluid flow in helical coiled tubing(CT) was carried out to reveal the flow characteristics and friction pressure loss law of the helical section.A set of regression correlations predicting friction factor of Newtonian fluid were proposed taking Dean number and the curvature as arguments and considering the effect of curvature and geometry of the pipe on the friction factor.And the proposed correlations were compared with other selected friction factor correlations.The results show that the friction pressure loss of the helical section is larger than the general friction pressure loss of the straight section due to the secondary flow,which can not be ignored.The prediction results of the proposed correlation for friction factor in the helical section agree well with the results of selected correlations with good applicability in laminar and turbulent flow area.And the feasibility of studying helical section with numerical simulation method was provided.The proposed friction factor prediction correlation for helical section can provide method and theoretical support for the CT follow-up hydrodynamic research.