Study on the restart algorithm for a buried hot oil pipeline based on wavelet collocation method

Abstract The influence of soil temperature field on the restart process of crude oil pipeline is not considered in previous studies. However, it cannot be ignored for the long-time restart of buried hot oil pipeline. Considering the long computation time for the solution of soil temperature field, the study on the hydraulic-thermal coupled acceleration algorithm for the restart process of buried hot oil pipeline is conducted. Firstly, the mathematical models considering the influence of soil temperature field are introduced in detail for the restart problem. Then based on wavelet collocation method, the adaptive gird is generated to reduce the computational cost of soil temperature field. Furthermore, the hydraulic-thermal coupled acceleration algorithm is proposed, which can realize the fast coupled solution of the restart process. Finally, the optimal values of threshold and coarsest level of resolution are investigated for the restart problem, and the time-adaptive strategy and no-time-adaptive strategy are compared. And the conclusions are drawn from the comparison and analysis of numerical results, which can provide beneficial guidance to the choices of threshold, coarsest level of resolution and adaptive strategy in future studies.

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