Title of Paper:A new modified Levenberg-Marquardt algorithm for identifying the temperature-dependent conductivity of solids based on the radial integration boundary element method

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Date of Publication:2019-12-01

Journal:INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

Included Journals:EI、SCIE

Volume:144

ISSN No.:0017-9310

Key Words:Levenberg-Marquardt algorithm; Complex variable derivative method; Radial integration boundary element method; Inverse heat conduction problem; Temperature-dependent conductivity

Abstract:In this paper, combination of radial integration boundary element method (RIBEM) with complex variable and Levenberg-Marquardt algorithm (LMA) is firstly proposed to identify temperature-dependent conductivity in the inverse heat conduction problem. To obtain the simulative temperature, radial integration boundary element method is used to solve the transient nonlinear heat conduction problem with temperature-dependent conductivity. What's more, RIBEM with complex variable, which transforms the real variables into complex ones in boundary element method, makes it possible to perform complex variable derivative method (CVDM) in LMA. Furthermore, because of the introduction of CVDM, the sensitivity coefficient matrix can be calculated accurately and efficiently, and then the identification of unknown variable can be achieved admirably in the inverse heat problem. Finally, different initial guess value and measurement errors are considered, respectively, and various numerical examples are presented to fully demonstrate the accuracy and feasibility of the proposed method in identifying temperature-dependent conductivity. (C) 2019 Elsevier Ltd. All rights reserved.