Niven Robert K
School of Engineering and Information Technology, The University of New South Wales, Canberra, ACT 2600, Australia.
Entropy (Basel). 2021 Nov 15;23(11):1515. doi: 10.3390/e23111515.
This study examines the invariance properties of the thermodynamic entropy production in its global (integral), local (differential), bilinear, and macroscopic formulations, including dimensional scaling, invariance to fixed displacements, rotations or reflections of the coordinates, time antisymmetry, Galilean invariance, and Lie point symmetry. The Lie invariance is shown to be the most general, encompassing the other invariances. In a shear-flow system involving fluid flow relative to a solid boundary at steady state, the Galilean invariance property is then shown to preference a unique pair of inertial frames of reference-here termed an -respectively moving with the solid or the mean fluid flow. This challenges the Newtonian viewpoint that all inertial frames of reference are equivalent. Furthermore, the existence of a shear flow subsystem with an entropic pair different to that of the surrounding system, or a subsystem with one or more changing entropic pair(s), requires a source of negentropy-a power source scaled by an absolute temperature-to drive the subsystem. Through the analysis of different shear flow subsystems, we present a series of governing principles to describe their entropic pairing properties and sources of negentropy. These are unaffected by Galilean transformations, and so can be understood to "lie above" the Galilean inertial framework of Newtonian mechanics. The analyses provide a new perspective into the field of , the study of the relative motions of objects with friction.
本研究考察了热力学熵产生在其全局（积分）、局部（微分）、双线性和宏观表述中的不变性特性，包括维度缩放、坐标的固定位移、旋转或反射不变性、时间反对称性、伽利略不变性和李点对称性。结果表明，李不变性是最普遍的，包含了其他不变性。在一个涉及稳态下流体相对于固体边界流动的剪切流系统中，伽利略不变性特性随后表明偏好一对独特的惯性参考系——这里分别称为与固体或平均流体流动一起移动的参考系。这挑战了牛顿的观点，即所有惯性参考系都是等效的。此外，存在一个熵对与周围系统不同的剪切流子系统，或一个具有一个或多个变化熵对的子系统，需要一个负熵源——一个由绝对温度缩放的动力源——来驱动该子系统。通过对不同剪切流子系统的分析，我们提出了一系列 governing principles 来描述它们的熵配对特性和负熵源。这些不受伽利略变换的影响，因此可以理解为“高于”牛顿力学的伽利略惯性框架。这些分析为研究有摩擦物体相对运动的领域提供了一个新的视角。
