A Comparative Study of the Harmonic and Arithmetic Averaging of Diffusion Coefficients for Non-linear Heat Conduction Problems

Kadioglu, Samet Y. ; Nourgaliev, Robert R. ; Mousseau, Vincent A.

Idaho National Laboratory

关键词: Discretization;    Diffusion;    99 General And Miscellaneous//Mathematics, Computing, And Information Science;    Subgrid Model;    Error Assesment;   

DOI  :  10.2172/928087
RP-ID  :  INL/EXT-08-13999
RP-ID  :  DE-AC07-99ID-13727
RP-ID  :  928087

美国|英语

来源: UNT Digital Library

【 摘 要 】

We perform a comparative study for the harmonic versus arithmetic averaging of the heat conduction coefficient when solving non-linear heat transfer problems. In literature, the harmonic average is the method of choice, because it is widely believed that the harmonic average is more accurate model. However, our analysis reveals that this is not necessarily true. For instance, we show a case in which the harmonic average is less accurate when a coarser mesh is used. More importantly, we demonstrated that if the boundary layers are finely resolved, then the harmonic and arithmetic averaging techniques are identical in the truncation error sense. Our analysis further reveals that the accuracy of these two techniques depends on how the physical problem is modeled.