The balance equation of angular momentum in anisotropic fluids includes a couple stress contribution, also responsible for an antisymmetric contribution to the force stress tensor. We herein derive all balance equations for the simplest anisotropic fluid, i.e., a polar fluid, using the GENERIC formalism of non-equilibrium thermodynamics. In doing so, we find that there is an inconsistency between the internal energy density evolution equation derived using non-equilibrium thermodynamics and the one usually considered in micropolar theory.

中文翻译：

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极性流体情况下微极性理论与非平衡热力学之间的不一致

各向异性流体中角动量的平衡方程包括一对应力贡献，也负责对力应力张量的反对称贡献。我们在此使用非平衡热力学的通用形式推导了最简单的各向异性流体（即极性流体）的所有平衡方程。在此过程中，我们发现使用非平衡热力学推导的内部能量密度演化方程与微极理论中通常考虑的内部能量密度演化方程之间存在不一致。