Phase transition induced by a shock wave in hard-sphere and hard-disk systems.
Phase transition induced by a shock wave in hard-sphere and hard-disk systems.
复制标题
DOI：
10.1063/1.2936990
复制
发表时间：
2008-08
期刊：
影响因子：
--
通讯作者：
N. Zhao;M. Sugiyama;T. Ruggeri
中科院分区：
文献类型：
--
作者：
N. Zhao;M. Sugiyama;T. Ruggeri
本文从欧拉方程组出发，结合热量和热状态方程，研究了硬球和硬盘系统中激波诱导的动态相变。首先分析了Rankine-Hugoniot条件。根据未扰动态（激波前的状态）的热力学量和激波强度对Hugoniot型进行了定量分类。特别是对Hugoniot在两种典型的可能情况（P-1和P-2）下的相变进行了详细的分析。当冲击强度改变时，在情况P-1中，相变发生在亚稳液态和稳定固态之间，而在情况P-2中，相变通过共存状态发生。其次，从最近的冲击波数学理论的观点讨论了这两种情况下的可接受性，并提出了一个规则与使用的最大熵产生率的规则，用于选择最可能的一个可能的情况下，即，最合适的本构方程，预测最可能的冲击波。根据这一规律，P-2情形下的本构方程是最有希望用于动态相变的本构方程。本文强调指出，硬球和硬盘系统是研究激波现象，包括更现实的凝聚态物质中的激波诱导相变的合适参考系统。
Dynamic phase transition induced by a shock wave in hard-sphere and hard-disk systems is studied on the basis of the system of Euler equations with caloric and thermal equations of state. First, Rankine-Hugoniot conditions are analyzed. The quantitative classification of Hugoniot types in terms of the thermodynamic quantities of the unperturbed state (the state before a shock wave) and the shock strength is made. Especially Hugoniot in typical two possible cases (P-1 and P-2) of the phase transition is analyzed in detail. In the case P-1 the phase transition occurs between a metastable liquid state and a stable solid state, and in the case P-2 the phase transition occurs through coexistence states, when the shock strength changes. Second, the admissibility of the two cases is discussed from a viewpoint of the recent mathematical theory of shock waves, and a rule with the use of the maximum entropy production rate is proposed as the rule for selecting the most probable one among the possible cases, that is, the most suitable constitutive equation that predicts the most probable shock wave. According to the rule, the constitutive equation in the case P-2 is the most promising one in the dynamic phase transition. It is emphasized that hard-sphere and hard-disk systems are suitable reference systems for studying shock wave phenomena including the shock-induced phase transition in more realistic condensed matters.