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Indexed by:期刊论文

Date of Publication:2021-03-05

Journal:JOURNAL OF COMPUTATIONAL SCIENCE

Volume:45

ISSN No.:1877-7503

Key Words:Reduced-order model(ROM); Proper orthogonal decomposition (POD); Nonlinear heat conduction; Transient analysis; Free element method(FREM)

Abstract:In this paper, the application of Free Element Method (FREM) is extended to the transient nonlinear heat conduction problems, and the characteristics of anisotropic, heterogeneous, temperature-dependent thermophysical properties and heat generation are also involved. In order to improve the efficiency during the nonlinear iterations, an alternating iteration strategy, FREM-ROM, is proposed, in which the proper orthogonal decomposition (POD) technique is used to establish a sectionalized extrapolation algorithm with lower dimensions and sufficiently high accuracy. This iteration strategy reduces the computational scale by using the Reduced-Order Model (ROM) technique and can guarantee the accuracy by continually correcting the database and POD bases every few time steps during the process of iterations. It also has the potential to be applied to other numerical methods for improved the efficiency. The accuracy and efficiency are examined by two numerical examples, in which the 2D example illustrates the relationship between truncated basis and accuracy in detail, and the heat transfer performance of a large-scale 3D cross-fin heat sink(CFHS) is investigated to highlight the efficiency advantages of solving large-scaled practical problems.