国外坛子上看到一个关于“Coefficient Ratio exceeds 1e08”的解释

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        最近在做一个电磁场分析，不过总是遇到一个很奇怪的warning：“Coefficient Ratio exceeds 1e08，check results”，百思不得其解，最后在国外的一个坛子上看到了一个同学的解释：
         
Hi Adam and Yongbing,

Actually, the coefficient ratio warning is probably because of your thermal
and electrical properties.

Depending on the material and the units you use, your thermal and electrical
values may differ significantly - this is possible with your materials as
well as your thermal and electrical contact conductance values. For
example, if you had copper in SI units, your thermal conductivity may be
around 400 W/m/K whereas your resistivity may be around 2e-8 ohm m, which
results in big differences in terms in the [K] matrix.

If you expect these values to differ significantly, you can ignore the
warning. The warning is usually there to make sure that in a single-field
analysis, you have input properties correctly. You will often see this
warning in coupled-field analyses because the values used in the two (or
more) physics may not be in the same order of magnitude.

Regards,
Sheldon

大意是说，不同材料之间的物性差距有可能很大，比如我所做的分析中包含了空气和铁的模型，空气基本不导磁，相对导磁率为1，而铁是磁的良导体，能达到10的四次方以上，当这些物性差距很大时，就会出现这个警告，如果你确定物性参数的数量级差距很大的话，这个警告完全可以忽略，否则就需要检查物性参数是否设置合理了。

希望会对各位同学有点帮助。

doraemoncc.bit

受教了，谢谢lz

tan2040504

感谢lz把这个国外的坛子发给我们撒
谢谢啦

suixiang

谢谢楼主