Method of Lagrange multipliers for exploitation of the entropy principle
Method of Lagrange multipliers for exploitation of the entropy principle
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DOI:
10.1007/bf00250688
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发表时间:
1972
影响因子:
2.5
通讯作者:
I. Liu
中科院分区:
文献类型:
--
作者:
I. Liu
In thermodynamics, whenever a material is subject to investigation of its properties, the entropy principle is used to impose restrictions on the constitutive relations for the material.There is not, so far, any simple method by which restrictions from the entropy principle can be derived for all kinds of different materials. Indeed, until very recently there was not even an entropy principle appropriate to all bodies. MULLER [1][2][3] has proposed such a general entropy principle, and here I suggest a simple method for its exploitation: the method of Lagrange multipliers. The entropy principle requires the constitutive relations to be such that every solution of the thermodynamic field equations satisfy the entropy inequality. To satisfy this requirement is not easy, since usually complicated calculations ensue. The method proposed here is intended to facilitate the solution of this problem. It can be described roughly as follows: