论文标题
压力 - 应变作为无碰撞等离子体的能量耗散估计值
Pressure-Strain Interaction as the Energy Dissipation Estimate in Collisionless Plasma
论文作者
论文摘要
弱碰撞等离子体中的耗散机制是几十年来没有共识解决方案的研究的话题。我们根据血浆湍流中的能量传递过程比较了几个能量耗散估计值,并为压力 - 应变相互作用提供了理由,作为对能量耗散速率的直接估计。在2.5D和3D动力学模拟中检查了全球和规模的能量平衡。我们表明,全球内部能量的增加和每个物种的温度升高是通过压力应变相互作用直接跟踪的。在考虑的所有模拟中,压力应变相互作用的不可压缩部分在其压缩部分上占主导地位。按比例的能量平衡通过尺度过滤的vlasov-Maxwell方程,动力学等离子体方法和滞后依赖性vonKármán-Howarth方程来量化,这是一种基于流体模型的方法。我们发现,在所有尺度上,能量平衡都完全满足,但是缺乏明确的惯性范围会影响惯性范围内不同项之间能量预算的分布。因此,在某些情况下,尤其是当系统中的比例分离未明确定义时,尤其是在某些情况下,与估计耗散率相对于估计耗散率的广泛使用是值得质疑的。相比之下,无论尺度分离如何,压力 - 应变的相互作用都可以精确平衡动力学尺度的耗散速率。
The dissipative mechanism in weakly collisional plasma is a topic that pervades decades of studies without a consensus solution. We compare several energy dissipation estimates based on energy transfer processes in plasma turbulence and provide justification for the pressure-strain interaction as a direct estimate of the energy dissipation rate. The global and scale-by-scale energy balances are examined in 2.5D and 3D kinetic simulations. We show that the global internal energy increase and the temperature enhancement of each species are directly tracked by the pressure-strain interaction. The incompressive part of the pressure-strain interaction dominates over its compressive part in all simulations considered. The scale-by-scale energy balance is quantified by scale filtered Vlasov-Maxwell equations, a kinetic plasma approach, and the lag dependent von Kármán-Howarth equation, an approach based on fluid models. We find that the energy balance is exactly satisfied across all scales, but the lack of a well-defined inertial range influences the distribution of the energy budget among different terms in the inertial range. Therefore, the widespread use of the Yaglom relation to estimating dissipation rate is questionable in some cases, especially when the scale separation in the system is not clearly defined. In contrast, the pressure-strain interaction balances exactly the dissipation rate at kinetic scales regardless of the scale separation.