This paper presents a novel implicit method of characteristics (MOC) utilizing pressure-referenced characteristic line correction that ensures the efficiency and reliability of transient flow analyses for natural gas pipelines. The conventional implicit MOC utilizes an inertial multiplier that results in issues associated with numerical dispersion and convergence in fast transient flows. This increases the computational cost compared to that of the explicit MOC, preventing the practical application of the implicit MOC. To address this issue, a pressure-referenced characteristic line correction method that guarantees second-order accuracy is proposed. The proposed method coordinates the characteristic line and corrects it using pressure gradients to enhance the computational efficiency and fidelity of the system. Quantitative and qualitative analyses were performed to verify the performance of the proposed method. It was confirmed that the proposed method outperformed the conventional technique in terms of computational cost and reliability when applied to fast transient flows. Compared with those of the conventional method, there were 40-fold and one-half reductions in computational cost and root mean square error, respectively, under a Courant–Friedrich–Lewy condition of 10.0. Additionally, the feasibility of the proposed method in practical pipeline analysis applications was confirmed through verification experiments for a real-world slow transient problem.

本文提出了一种新的隐式特性方法(MOC)，利用压力参考特性线校正，确保天然气管道瞬态流动分析的效率和可靠性。传统的隐式 MOC 使用惯性乘法器，导致与快速瞬态流中的数值离散和收敛相关的问题。与显式 MOC 相比，这增加了计算成本，阻碍了隐式 MOC 的实际应用。针对这一问题，提出了一种保证二阶精度的压力参考特征线校正方法。所提出的方法协调特征线并使用压力梯度，以提高系统的计算效率和保真度。进行了定量和定性分析以验证所提出方法的性能。经证实，当应用于快速瞬态流时，所提出的方法在计算成本和可靠性方面优于传统技术。与传统方法相比，在 Courant-Friedrich-Lewy 条件为 10.0 下，计算成本和均方根误差分别降低了 40 倍和二分之一。此外，通过对真实世界慢瞬态问题的验证实验，证实了所提出方法在实际管道分析应用中的可行性。