Effective numerical methods for calculating non-stationary heat and glaciation dynamic processes for offshore gas pipelines

For offshore gas pipelines in the northern seas the computation of the total heat flux from ambient in every cross section of the pipeline involves solutions of various non-stationary heat problems, in particular, the one- and multidimensional single- and two-phase Stefan problems. In this paper, we have developed a novel numerical method with increased accuracy in solving one-dimensional single- and two-phase Stefan problems. Results of a comparative analysis of the various numerical techniques with respect to its effectiveness in solving to two-dimensional heat conduction problems in the absence of axial symmetry is presented. The calculation by chosen effective numerical method of the total heat flux into a gas pipeline buried in soil under different conditions presented. (C) 2020 Elsevier Ltd. All rights reserved.