Special Computational Gas Flow Simulation Methods for Trunkline Network Failures

Abstract

We consider two new methods for numerical solution of a complete system of partial differential equations describing the flow of a gas mixture in pipeline systems. The first method tracks Lagrangian particles as they move together with the flow of transported fluid. When implementing this method, the flow parameters are found by means of a difference scheme, and the distribution of mass fractions of components and enthalpy of matter along the pipeline, by analyzing the motion of the Lagrangian particles. If we ignore the processes of diffusion, these particles must preserve their composition. The energy equation without diffusion and heat conduction reduces to an ordinary differential equation. The method proposed is free of artificial viscosity, because, for example, when considering the equation of continuity of components, variations in their specific mass fractions at any point in space are related only to physically meaningful processes, namely, to the inflow of “new” particles (with “new" specific mass fractions of the components). The second method includes constructing spline functions along the space and time coordinates of the computational mesh subject to the fulfillment of differential equations at its nodes. The use of splines of high orders of approximation improves the accuracy of modeling.

Keywords: Lagrangian Particle Method, Spline Scheme, Computer Gas Dynamics Simulator, Multi-Component Gas Mixture

DOI: 10.54941/ahfe100416