Helmholtz or Kelvin Cloud Waves

Ubiquity of Kelvin–Helmholtz waves at Earth's magnetopause

Magnetic reconnection is believed to be the dominant process by which solar wind plasma enters the magnetosphere. However, for periods of northward interplanetary magnetic field (IMF) reconnection is less likely at the dayside magnetopause, and Kelvin-Helmholtz waves (KHWs) may be important agents for plasma entry and for the excitation of ultra-low-frequency (ULF) waves. The relative importanc...

Kelvin-Helmholtz Instabilities

Kelvin-helmholtz Instability by Sph

In this paper, we have modeled the Kelvin-Helmholtz Instability (KHI) problem of an incompressible two-phase immiscible fluid in a stratified inviscid shear flow with interfacial tension using Smoothed Particle Hydrodynamics (SPH) method. The time dependent evolution of the two-fluid interface over a wide range of Richardson number (Ri) and for three different density ratios is numerically inve...

Differential Diffusion in Breaking Kelvin–Helmholtz Billows

Direct numerical simulations are used to compare turbulent diffusivities of heat and salt during the growth and collapse of Kelvin–Helmholtz billows. The ratio of diffusivities is obtained as a function of buoyancy Reynolds number Reb and of the density ratio R (the ratio of the contributions of heat and salt to the density stratification). The diffusivity ratio is generally less than unity (he...

Band gaps and the Kelvin-Helmholtz instability.

We consider the linear stability of two inviscid fluids, in the presence of gravity, sheared past each other and separated by a flexible plate. Conditions for exponential growth of velocity perturbations are found as functions of the flexural rigidity of the plate and the shear rate. This Kelvin-Helmholtz instability is then analyzed in the presence of plates with spatially periodic (with perio...