simulation of transient compressible ideal gas flow in a high pressure branched pipeline

nowadays, compressible flow transmission pipelines are used in many industrial processes. pipelines in chemical processes, gas turbine power plants, natural gas transmission lines, and high pressure steam transmission pipelines are some industrial examples. therefore, learning the manner of treatment of a transient compressible fluid flow in pipelines with junctions and branches is important. in this paper, the attempt is to derive the governing equations in compressible fluid flow in a fixed area pipeline in the presence of friction. to achieve this, a numerical method of analysis (mccormack) is used. also the method of characteristics is added to solve the problem in the junctions. finally, a theoretical case and an industrial one are investigated and some common transient processes are simulated. in addition, the effects of boundary conditions on the flow characteristics, such as pressure and flow rates, are presented.