OPTIMAL NUMERICAL METHOD FOR SIMULATING DYNAMIC FLOW OF GAS IN PIPELINES

SUMMARY Finite difference methods for solving the linear model describing unsteady state flow in pipelines are considered in the present paper. These methods are compared with each other in order to determine the best one, which meets the criteria of accuracy and relatively small computation time. Gas plays an extremely significant role in the fuel-energetic balance of most industrialized countries of the world. High calorific value combined with the facility of transport places it in the group of most valuable row materials. For that very reason its economic utilization is a problem of major importance. It should be dealt with by the optimization (with regard to a given criterion) of both the process of on-line control of gas transport system and the design of new or the reconstruction of existing networks. One cannot properly realize any of the enumerated tasks without first solving problems raised by network simulation. In the process of system control the simulation supplies us with the information on the values of pressures and flows indispensable in the selection of suitable parameters both for compressor stations and reduction stations. In the process of design the simulation allows us to correctly select network configurations, geometrical dimensions of pipelines, as well as the sites of both compressor and reduction stations for given parameters of gas supply and demand. Two kinds of simulation are commonly differentiated: the static one and the dynamic one. The present article deals with the dynamic simulation, i.e. with the case in which the parameters characterizing the gas supply of the system and its load are functions of time (in the static simulation they are independent of time). Correct simulation of dynamic properties necessitates the selection of the suitable mathematical model and the suitable numerical method enabling us to solve this model. Finite difference methods for solving the model elaborated in Reference 1 are considered in the present paper. These methods are compared with each other in order to determine the best one, which meets the criteria of accuracy and relatively small computation time. The investigations described have been undertaken chiefly because in many professional publications (e.g. References 2-4) various numerical schemes had been advanced, whereas the criteria for their selection had not been presented. 0271-2091/83/020125- 11$01.10 0 1983 by John Wiley & Sons, Ltd.