An Efficient Transient Simulation Framework for Natural Gas Networks Using Time-Iterative Decoupling

As natural gas networks expand and become more topologically complex, and as demands for component and calorific value tracking increase, transient simulation becomes increasingly computationally challenging, creating an urgent need for more efficient simulation techniques. Owing to the strong causality inherent in transient gas network simulations, conventional approaches rely on time-marching schemes, leaving the time dimension largely unexplored. In this work, a Parallel-in-Time (PinT) framework termed TIDE, based on time-marching principles and the memoryless characteristics of the governing equations, is proposed to accelerate transient simulations of natural gas networks along the temporal dimension. By combining the physical characteristics of hydraulic, thermal, and compositional variables with the mathematical properties of their centrally discretized governing equations, the error behavior of transient simulations is analyzed, leading to a targeted hybrid strategy based on pseudo-time steps and overlapping time domains. The effectiveness of TIDE is validated on a natural gas network with complex topology, demonstrating that its solutions achieve approximately 99% accuracy compared with conventional time-marching and TGNET. Furthermore, taking the local smoothness at temporal interfaces as the criterion for acceptable error, TIDE with a decomposition granularity of four achieves speedups of 71.39%, 64.92%, and 53.43% in hydraulic simulation, thermal simulation, and component tracking, respectively, relative to the time-marching approach. Within the field of transient simulation of natural gas networks, TIDE represents the first systematic attempt to exploit parallelism along the time dimension, providing effective methodological guidance and theoretical support for related studies.