State Key Laboratory for Turbulence and Complex Systems, Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China.
Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA.
Phys Rev E. 2017 Jun;95(6-1):061201. doi: 10.1103/PhysRevE.95.061201. Epub 2017 Jun 29.
Analysis of the Vlasov-Maxwell equations from the perspective of turbulence cascade clarifies the role of electromagnetic work, and reveals the importance of the pressure-strain relation in generating internal energy. Particle-in-cell simulation demonstrates the relative importance of the several energy exchange terms, indicating that the traceless pressure-strain interaction "Pi-D" is of particular importance for both electrons and protons. The Pi-D interaction and the second tensor invariants of the strain are highly localized in similar spatial regions, indicating that energy transfer occurs preferentially in coherent structures. The collisionless turbulence cascade may be fruitfully explored by study of these energy transfer channels, in addition to examining transfer across spatial scales.
从湍流级串的角度分析 Vlasov-Maxwell 方程，阐明了电磁功的作用，揭示了压力应变关系在产生内能方面的重要性。粒子模拟表明，几种能量交换项的相对重要性，表明无迹压力应变相互作用“Pi-D”对电子和质子都非常重要。Pi-D 相互作用和应变的第二张量不变量在相似的空间区域高度局域化，表明能量转移优先发生在相干结构中。除了研究跨空间尺度的转移外，通过研究这些能量转移通道，还可以有效地探索无碰撞湍流产级串。
