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arXiv 2602.00658physics.comp-phphysics.flu-dyn
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一种无振荡的真实流体准守恒有限体积方法用于跨临界和相变流动

An Oscillation-Free Real Fluid Quasi-Conservative Finite Volume Method for Transcritical and Phase-Change Flows

National University of Defense Technology(国防科技大学);Shanghai Jiao Tong University(上海交通大学)

Haotong Bai, Wenjia Xie, Yixin Yang, Ping Yi, Mingbo Sun

AI总结:

提出一种真实流体准守恒(RFQC)有限体积方法,通过局部线性化状态方程并构造冻结Grüneisen系数和线性化余项,消除跨临界和相变流动中激波引起的压力振荡,实现准确鲁棒的模拟。

摘要:

开发了一种新的真实流体准守恒(RFQC)有限体积方法,用于处理涉及跨临界和相变流动中激波的真实流体数值模拟。为了消除完全守恒格式中固有的虚假压力振荡,我们将最初为两相流设计的经典准守恒方法扩展到由任意状态方程(EoS)控制的真实流体。RFQC方法在每个网格点和时间步局部线性化真实流体EoS,通过两个平流方程构造并演化冻结的Grüneisen系数$\Gamma$和线性化余项$E_0$。在每个时间步结束时,利用演化的$\Gamma$和$E_0$重构无振荡的压力场,然后对守恒变量进行热力学重投影。理论分析表明,在光滑区域,RFQC方法引入的能量守恒误差是时间步长主导的二阶小量;在间断区域,该误差由熵增率决定,从而与激波捕捉方法的固有截断误差保持一致。一系列数值测试验证了该方法能够稳健地模拟复杂流动过程,仅产生微小的能量守恒误差,包括跨临界流动、相变和激波-界面相互作用。RFQC方法在捕捉激波和相变方面被证明既准确又鲁棒。

英文摘要:

A new Real Fluid Quasi-Conservative (RFQC) finite volume method is developed to address the numerical simulation of real fluids involving shock waves in transcritical and phase-change flows. To eliminate the spurious pressure oscillations inherent in fully conservative schemes, we extend the classic quasi-conservative method, originally designed for two-phase flows, to real fluids governed by arbitrary equations of state (EoS). The RFQC method locally linearizes the real fluid EoS at each grid point and time step, constructing and evolving the frozen Grüneisen coefficient $Γ$ and the linearization remainder $E_0$ via two advection equations. At the end of each time step, the evolved $Γ$ and $E_0$ are utilized to reconstruct the oscillation-free pressure field, followed by a thermodynamic re-projection applied to the conserved variables. Theoretical analysis demonstrates that, in smooth regions, the energy conservation error introduced by the RFQC method is a second-order small term dominated by the time-step. In discontinuous regions, this error is determined by the entropy increase rate, thereby maintaining consistency with the inherent truncation error of shock-capturing methods. A series of numerical tests verifies that the method can robustly simulate complex flow processes with only minor energy conservation errors, including transcritical flows, phase transitions, and shock-interface interactions. The RFQC method is proven to be both accurate and robust in capturing shock waves and phase transitions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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