Leilei Chen¹, Kunpeng Li¹, Xuan Peng², Haojie Lian^3,4,*, Xiao Lin⁵, Zhuojia Fu⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 125-146, 2021, DOI:10.32604/cmes.2021.012821 - 22 December 2020

Abstract This paper presents an isogeometric boundary element method (IGABEM) for transient heat conduction analysis. The Non-Uniform Rational B-spline (NURBS) basis functions, which are used to construct the geometry of the structures, are employed to discretize the physical unknowns in the boundary integral formulations of the governing equations. B´ezier extraction technique is employed to accelerate the evaluation of NURBS basis functions. We adopt a radial integration method to address the additional domain integrals. The numerical examples demonstrate the advantage of IGABEM in dimension reduction and the seamless connection between CAD and numerical analysis. More >

Fuyong Su^a,*, Rui Song^a , Peiwei Ni^a , Zhi Wen^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-5, 2019, DOI:10.5098/hmt.12.25

Abstract A mathematical model of the inverse heat transfer problem of blast furnace lining is established in this study. Following the identification of the boundary conditions of the model, the inverse problem via the conjugate gradient method was decomposed into three issues: the direct problem, the sensitivity problem, and the adjoint problem. The feasibility of the model was verified through two types of real inner wall boundary shape functions. The effects of the initial inner wall boundary shape function and the number of measuring points are also investigated. Results showed that the accuracy of the inverse More >

Hai-Dong Wanga , Zeng-Yuan Guo^a,*

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-12, 2019, DOI:10.5098/hmt.13.20

Abstract The classical heat transfer theory is established on the empirical models of Fourier’s heat conduction law and Newton’s cooling law. Although the classical theory has been successfully used in a wide range of industrial engineering applications, it lacks deep understanding of the physical mechanisms for energy transport and analytical methodology based on solid mathematical and mechanical principles. The rapid development of modern science and technology challenges the traditional heat transfer theory in two aspects: (1) Fourier’s law of heat conduction is no longer valid under the ultra-fast laser heating or nanoscale conditions; (2) The optimization… More >

Chihyu Liu¹, Chengyu Ku^1,2,*, Jingen Xiao¹, Weichung Yeih^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 229-252, 2019, DOI:10.31614/cmes.2019.04376

Abstract In this article, a meshless method using the spacetime collocation for solving the two-dimensional backward heat conduction problem (BHCP) is proposed. The spacetime collocation meshless method (SCMM) is to derive the general solutions as the basis functions for the two-dimensional transient heat equation using the separation of variables. Numerical solutions of the heat conduction problem are expressed as a series using the addition theorem. Because the basis functions are the general solutions of the governing equation, the boundary points may be collocated on the spacetime boundary of the domain. The proposed method is verified by More >

R. Rajaraman^a , L. Anna Gowsalya^b,*, R. Velraj^c

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-8, 2018, DOI:10.5098/hmt.11.23

Abstract To get accurate results in casting simulations, prediction of interfacial heat transfer coefficient (IHTC) is imperative. In this paper an attempt has been made for estimating IHTC during solidification process of a rectangular aluminium alloy casting in a sand mould. The cast temperature and mould temperature are measured during the experimental process at different time intervals during the process of solidification. Two different inverse methods, namely control volume and Beck’s approach are used to estimate the heat flux and temperature at the mould surface by using the experimentally measured temperatures. In the case of control More >

Yiqiang Li¹, Liang Ma², Zhiqiang Yang³, Xiaofei Guan⁴, Yufeng Nie¹, Zihao Yang^{1, 2}

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.1, pp. 1-24, 2018, DOI:10.3970/cmes.2018.115.001

Abstract This paper is devoted to the homogenization and statistical multiscale analysis of a transient heat conduction problem in random porous materials with a nonlinear radiation boundary condition. A novel statistical multiscale analysis method based on the two-scale asymptotic expansion is proposed. In the statistical multiscale formulations, a unified linear homogenization procedure is established and the second-order correctors are introduced for modeling the nonlinear radiative heat transfer in random perforations, which are our main contributions. Besides, a numerical algorithm based on the statistical multiscale method is given in details. Numerical results prove the accuracy and efficiency More >

Shenghu Ding^1,*, Qingnan Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.3, pp. 335-349, 2018, DOI:10.3970/cmes.2018.114.335

Abstract A multi-layered model for heat conduction analysis of a thermoelectric material strip (TEMs) with a Griffith crack under the electric flux and energy flux load has been developed. The materials parameters of the TEMs vary continuously in an arbitrary manner. To derive the solution, the TEMs is divided into several sub-layers with different material properties. The mixed boundary problem is reduced to a system of singular integral equations, which are solved numerically. The effect of strip width on the electric flux intensity factor and thermal flux intensity factor are studied. More >

Xu Liu¹, Guojian Shao¹, Xingxing Yue^2,*, Qingbin Yang³, Jingbo Su⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.2, pp. 189-211, 2018, DOI:10.31614/cmes.2018.03947

Abstract This paper aims to apply a virtual boundary element method (VBEM) to solve the inverse problems of three-dimensional heat conduction in orthotropic media. This method avoids the singular integrations in the conventional boundary element method, and can be treated as a potential approach for solving the inverse problems of the heat conduction owing to the boundary-only discretization and semi-analytical algorithm. When the VBEM is applied to the inverse problems, the numerical instability may occur if a virtual boundary is not properly chosen. The method encounters a highly ill-conditioned matrix for the larger distance between the… More >

Haolong Chen^1,2, Bo Yu¹, Huanlin Zhou^1*, Zeng Meng¹

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 271-290, 2017, DOI:10.3970/cmc.2017.053.271

Abstract The cuckoo search algorithm (CS) is improved by using the conjugate gradient method(CGM), and the CS-CGM is proposed. The unknown inner boundary shapes are generated randomly and evolved by Lévy flights and elimination mechanism in the CS and CS-CGM. The CS, CGM and CS-CGM are examined for the prediction of a pipe’s inner surface. The direct problem is two-dimensional transient heat conduction in functionally graded materials (FGMs). Firstly, the radial integration boundary element method (RIBEM) is applied to solve the direct problem. Then the three methods are compared to identify the pipe’s inner surfacewith the… More >

Antoine Fabre¹, Jordan Hristov^2*, Rachid Bennacer¹

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.2, pp. 69-85, 2016, DOI:10.3970/fdmp.2016.012.069

Abstract Closed form approximate solutions to nonlinear transient heat conduction with linear power-law k = k₀(1±βT^m) temperature-dependent thermal diffusivity have been developed by the integral-balance integral method under transient conditions. The solutions use improved direct approaches of the integral method and avoid the commonly used linearization by the Kirchhoff transformation. The main steps in the new solutions are improvements in the integration technique of the double-integration technique and the optimization of the exponent of the approximate parabolic profile with unspecified exponent. Solutions to Dirichlet boundary condition problem have been developed as examples by the classical Heat-balance Integral More >