Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Nuclear Research Center - Negev, Beer Sheva 84190, Israel.
Phys Rev Lett. 2015 Oct 2;115(14):145001. doi: 10.1103/PhysRevLett.115.145001. Epub 2015 Oct 1.
We report the first observation, in a supersonic flow, of the evolution of the Kelvin-Helmholtz instability from a single-mode initial condition. To obtain these data, we used a novel experimental system to produce a steady shock wave of unprecedented duration in a laser-driven experiment. The shocked, flowing material creates a shear layer between two plasmas at high energy density. We measured the resulting interface structure using radiography. Hydrodynamic simulations reproduce the large-scale structures very well and the medium-scale structures fairly well, and imply that we observed the expected reduction in growth rate for supersonic shear flow.
我们首次在超声速流中观察到了开尔文-亥姆霍兹不稳定性从单一模式初始条件的演化。为了获得这些数据，我们使用了一种新颖的实验系统，在激光驱动实验中产生了前所未有的持续时间的稳定激波。被激波压缩的流动物质在高能量密度下在两个等离子体之间形成了一个剪切层。我们使用射线照相术测量了由此产生的界面结构。流体动力学模拟很好地再现了大尺度结构，也相当好地再现了中尺度结构，并表明我们观察到了预期的超音速剪切流增长率的降低。
