Papers by Author: Vadim Seleznev

Abstract: The article describes numerical method of physical gas flow parameters recovery at accidents investigation, which are conditioned by guillotine rupture of a segment in gas trunkline and distribution pipeline systems. The information about full-scale measurements of time dependences of gas flow parameters at defined points inside pipelines system and at its boundaries is the base for recovery implementation at numerical investigation of accidents. Numerical recovery is carried out by defining and solving a special identification problem.

Abstract: The article describes algorithm for optimization of discrepancies in natural gas supply to consumers. Numerical monitoring makes it possible to obtain computational estimates of actual gas deliveries over given time spans and to estimate their difference from corresponding values reported by gas consumers. Mathematical analysis of the discrepancy is based on a statement and numerical solution of identification problem of a physically proved gas dynamics mode of natural gas transmission through specified gas distribution networks. The identified mode parameters should have a minimum discrepancy with field measurements of gas transport at specified reference points of the simulated pipeline network.

Abstract: At present day pipe mill engineers have to deal with challenging technological problems of heavy-wall and high strength line pipe manufacturing. Numerical analysis of welded large-diameter pipe manufacturing stages is the most efficient way to solve these problems. Corresponding computational technologies and applied software was developed at Physical & Technical Center. Numerical structural analysis of steel plates at various stages of line pipe manufacturing is performed by the finite element method accounting for geometric and material nonlinearities. The only thing to be done by the engineer in such analysis is to specify required input parameters. All the further process is software-controlled. The discrepancy between the numerical analysis results and measured data in the overwhelming majority cases did not exceed 1%.