Modeling the Stages of Verification of the Suitability of a Short Section of a Gas Pipeline for Operation

When modeling the processes of gas injection into an elementary section and gas outflow from it into an unlimited space, quasi-one-dimensional equations of gas pipeline transport in the approximation of a short pipeline are used, when the gas pressure gradient is formed only under the influence of the local component of the gas inertia force, and N.E. Zhukovsky’s formula on the gas outflow rate. The equations for the conservation of momentum and mass are linearized with the introduction of the gas mass flow rate, and the first boundary condition is presented as a linear dependence on the sought functions. The solution area is divided into rectangles with the dimensions of the section length of the section and the conditional period of the problem, which corresponds to the travel time of the perturbation over the entire length of the section. For the first conditional period, the formulas for calculating the pressure and gas mass flow rate are obtained by the method of characteristics. The ways of using these formulas to obtain a solution for the subsequent conditional periods are shown. Separate results of the calculations for the pressure, mass flow, and gas flow rate are presented for constant values of the functions involved in the boundary conditions. It is found that the difference between the external pressure and the gas pressure in the subregions, as well as the gas mass flow rate, decreases exponentially over time.