EPANET is one of the most commonly used open-source programs in hydraulic modelling water distribution networks (WDNs), based on steady-state and extended period simulation approaches. These approaches effectively estimate flow capacity and average pressures in networks; however, EPANET is not yet fully effective in modelling incompressible unsteady flows in WDNs. In this study, the hydraulic solver capacity of EPANET 3 is extended with the Rigid Water Column Global Gradient Algorithm (RWC-GGA) to model incompressible unsteady flow hydraulics in WDNs. Moreover, we incorporated dynamically more accurate valve expressions than the existing ones in the default EPANET code and introduced a new global convergence algorithm, Convergence Tracking Control Method (CTCM), in the solver code. The RWC-GGA, CTCM, and valve expressions are tested and validated in three different WDNs varying from simple to sophisticated set-ups. The results show that incompressible unsteady flows can be modelled with RWC-CGA and dynamic valve representations. Finally, the convergence problem due to the valve motion and the pressure-dependent algorithm (PDA) is solved by the implemented global convergence algorithm, i.e. CTCM.

EPANET 是水力建模配水网络 (WDN) 中最常用的开源程序之一，它基于稳态和延长周期模拟方法。这些方法有效地估计了网络中的流量和平均压力；然而，EPANET 在模拟 WDN 中不可压缩的非定常流动方面尚未完全有效。在这项研究中，EPANET 3 的水力求解器能力通过刚性水柱全局梯度算法 (RWC-GGA) 扩展，以模拟 WDN 中的不可压缩非定常流动水力。此外，我们在默认的 EPANET 代码中加入了比现有更精确的阀门表达式，并在求解器代码中引入了一种新的全局收敛算法，收敛跟踪控制方法 (CTCM)。RWC-GGA、CTCM、和阀门表达式在三种不同的 WDN 中进行测试和验证，从简单到复杂的设置。结果表明，不可压缩的非定常流动可以用 RWC-CGA 和动态阀门表示进行建模。最后，由阀门运动和压力相关算法（PDA）引起的收敛问题通过实施的全局收敛算法，即CTCM来解决。