CHINESE JOURNAL OF COMPUTATIONAL PHYSICS ›› 2017, Vol. 34 ›› Issue (3): 283-293.

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Conservative Positivity-Preserving Algorithm for Kershaw Scheme of Anisotropic Diffusion Problems

CAO Fujun1,2,3, YAO Yanzhong2   

  1. 1. School of Mathematical Science, University of Science and Technology of China, Hefei 230026, China;
    2. National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100088, China;
    3. School of Science, Inner Mongolia University of Science and Technology, Baotou 014010, China
  • Received:2016-03-11 Revised:2016-06-16 Online:2017-05-25 Published:2017-05-25

Abstract: Kershaw scheme is not positivity-preserving. Negative values emerge in numerical simulation for anisotropic diffusion equations on both orthogonal and distorted meshes. A conservative enforcing negative value to zero(CENZ) algorithm is proposed, which is an improvement of traditional method. It not only repairs numerical solution nonnegative, but also keeps local conservation of energy fluxes. Numerical examples demonstrate that the method is not limited by anisotropic ratio of diffusion coefficients. The algorithm can be used for numerical solution of finite volume schemes which violate monotony or positivity-preserving.

Key words: positivity-preserving, conservation, anisotropic diffusion, distorted mesh

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