Non-isothermal Transient Flow Analysis in Gas Pipelines Using a linearized Flux Splitting Numerical Scheme

Numerical simulation of non-isothermal transient gas flow is performed using implicit Steger-Warming finite difference method. Because of nonlinearity of the governing equations، they are linearized at each time step. The linearization either reduces computational effort or analyzes the flowfield more conveniently. In order to validate and evaluate the accuracy of current numerical method، Fanno and shock tube flows are investigated first. Then، transient flow in a gas pipeline that its inlet pressure changes with time is simulated. The results of present study show that Steger-Warming finite difference scheme can well captured the sudden changes in the flowfield. Moreover، the present method is able to analyze transient gas flows as nearly accurate as the nonlinear one with less computational effort.