搜索结果: 1-15 共查到“Kelvin-Helmholtz”相关记录15条 . 查询时间(0.053 秒)
Kelvin-Helmholtz（KH）不稳定性是一种由边界剪切流引起的不稳定性，在具有全球性磁场的行星（如地球和水星）以及没有全球磁场的行星（如金星和火星）的等离子环境中广泛存在。KH不稳定性发展到非线性阶段时会产生涡旋，其运动可以扭曲磁场并引起磁场拓扑的改变，导致等离子云的产生并从行星电离层脱离，造成重离子的丢失。KH不稳定性对边界层质量、动量和能量传输都有显著影响，因此在行星的等离子环境研究...
中国科学院国家空间科学中心科研人员与合作者首次在卫星观测中发现Kelvin-Helmholtz涡旋中嵌套Rayleigh-Taylor不稳定性的证据（图）
卫星观测 Kelvin-Helmholtz涡旋 Rayleigh-Taylor不稳定性
2023/2/16
太阳风向磁层的传输是磁层物理研究的一个基本问题。太阳风是太阳大气向外膨胀而形成的超声速带电粒子流，当太阳风遇到地球内禀磁场的阻挡时，会形成一个被称为地球磁层的空腔，空腔的外边界称为磁层顶。由于磁冻结效应（就像串绳约束着它所贯穿的许多珠子），磁层顶把来自地球的热等离子体与来自太阳风的冷等离子体隔开，使太阳风在这个空腔外围绕过，从而像盾牌一样为空腔里的地球提供了免于太阳风直接轰击的天然屏护，这是地球上...
中国科学院国家空间中心科研人员与合作者首次在卫星观测中发现Kelvin-Helmholtz涡旋中嵌套Rayleigh-Taylor不稳定性的证据（图）
卫星观测 磁层物理 热等离子体
2023/8/22
太阳风向磁层的传输是研究的一个基本问题。太阳风是太阳大气向外膨胀而形成的超声速带电粒子流，当太阳风遇到地球内禀磁场的阻挡时，会形成一个被称为地球磁层的空腔，空腔的外边界称为磁层顶。由于磁冻结效应（就像串绳约束着它所贯穿的许多珠子），磁层顶把来自地球的热等离子体与来自太阳风的冷等离子体隔开，使太阳风在这个空腔外围绕过，从而像盾牌一样为空腔里的地球提供了免于太阳风直接轰击的天然屏护，这是地球上存在宜居...
Kelvin-Helmholtz (KH) instability, characterized by the distinctive
finite-amplitude billows it generates, is an important mechanism in the development
of turbulence in the stratified interior of ...
近日，中国科学院空间科学与应用研究中心空间天气国家重点实验室科研人员燕广庆等及时追踪了THEMIS卫星的观测资料并进行了细致分析，获取了行星际磁场南向期间Kelvin-Helmholtz涡旋的难得观测证据，进一步通过卫星观测事实证明了在行星际磁场南向期间也可以发生具有规则周期性的Kelvin-Helmholtz涡旋，客观地打破了Kelvin-Helmholtz涡旋只能在行星际磁场北向条件下发生的传...
Kelvin-Helmholtz不稳定性是液滴变形和破碎的重要机制。本文采用基于 Cut Cell方法和 LevelSet函数的满足守恒率和相容性的尖锐界面可压缩多相流计算流体力学方法模拟研究液滴在高速气流中表面的不稳定性问题。在贴体结构化网格的帮助下，我们比较好的解析出液滴附近气体的边界层。模拟结果和实验结果符合的很好。在计算流体力学模拟的帮助下，我们研究液滴和气体界面附近的空气动力学现象，以及...
Large-scale magnetic field generation via the Kelvin-Helmholtz instability
Large-scale magnetic field generation Kelvin-Helmholtz instability
2011/10/18
We present the first self-consistent three-dimensional particle-in-cell simulations of the Kelvin-Helmholtz instability (KHI) in an unmagnetized scenario. We discuss the main features, including densi...
The Kelvin-Helmholtz instability in weakly ionised plasmas: Ambipolar dominated and Hall dominated flows
mhd – instabilities – ISM:clouds – ISM:kinematics and dynamics
2011/10/12
The Kelvin-Helmholtz instability is well known to be capable of converting well-ordered flows into more disordered, even turbulent, flows. As such it could represent a path by which the energy in, for...
Lattice Boltzmann study on Kelvin-Helmholtz instability: the roles of velocity and density gradients
Soft Condensed Matter (cond-mat.soft) Cellular Automata and Lattice Gases (nlin.CG) Computational Physics (physics.comp-ph) Plasma Physics (physics.plasm-ph)
2010/11/10
A two-dimensional lattice Boltzmann model with 19 discrete velocities for compressible Euler equations is proposed (D2V19-LBM). The fifth-order Weighted Essentially Non-Oscillatory (5th-WENO) finite d...
Forming Planetesimals by Gravitational Instability: I. The Role of the Richardson Number in Triggering the Kelvin-Helmholtz Instability
Earth and Planetary Astrophysics (astro-ph.EP)
2010/12/23
Gravitational instability (GI) of a dust-rich layer at the midplane of a gaseous circumstellar disk is one proposed mechanism to form planetesimals, the building blocks of rocky planets and gas giant ...
Coupling between reconnection and Kelvin-Helmholtz instabilities in collisionless plasmas
reconnection Kelvin-Helmholtz instabilities collisionless plasmas
2009/10/30
In a collisionless plasma, when reconnection instability takes place, strong shear flows may develop. Under appropriate conditions these shear flows become unstable to the Kelvin-Helmholtz instability...
KELVIN-HELMHOLTZ DISCONTINUITY IN TWO SUPERPOSED VISCOUS CONDUCTING FLUIDS IN A HORIZONTAL MAGNETIC FIELD
viscosity porous medium streaming velocity
2009/10/14
The Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids has been investigated in the taking account of effects of surface tension, when the whole system is immersed in a uniform...
WENO有限差分格式有较高的分辨精度，适合复杂流场的计算，在国际上被广泛采用。本文利用WENO有限差分格式求解2维守恒型欧拉方程，实现了对无粘流体中Kelvin-Helmholtz不稳定性的数值模拟。速度剪切方向采用周期边界条件；扰动增长方向采用嵌边出流边界条件，一个不稳定波长分布64个网格。数值模拟给出的扰动幅值线性增长率与线性稳定性分析给出的结果很好符合，显示了该格式的有效性和精度。数值模拟给...
摘要在状态方程为压力是密度的任意单值函数形式情况下，运用小扰动分析和奇异摄动法，给出了流体微扰方程渐近解和界面不稳定性的色散关系. 分析表明：对Rayleigh-Taylor不稳定性，在重力场作用下流体可压缩性形成的密度分布是致稳因素；而扰动流体的膨胀收缩效应助长不稳定性的发展；上层重流体的可压缩性是稳定因素，下层轻流体可压缩性是失稳因素. 而对Kelvin-Helmholtz不稳定性，流体可压缩...
On the MHD Boundary of Kelvin-Helmholtz Stability Diagram at Large Wavelengths
the MHD Boundary Kelvin-Helmholtz Stability Diagram Large Wavelengths
2010/10/27
Working within the domain of inviscid incompressible MHD theory, we found that a tangential discontinuity (TD) separating two uniform regions of different density, velocity and magnetic field may be K...