Kelvin-Helmholtz instability in a weakly ionized layer

TL;DR

This paper analyzes how the finite thickness of a weakly ionized layer influences the Kelvin-Helmholtz instability, revealing that layer thickness stabilizes certain modes and affects mode transitions depending on magnetic strength.

Contribution

It provides a linear theoretical framework for understanding the impact of layer thickness on Kelvin-Helmholtz instability in weakly ionized media, highlighting the stabilizing effects.

Findings

Layer thickness stabilizes dominant growing modes.

Wavelengths comparable to layer thickness are significantly affected.

Mode transition depends on magnetic strength and layer thickness.

Abstract

We study the linear theory of Kelvin-Helmholtz instability in a layer of ions and neutrals with finite thickness. In the short wavelength limit the thickness of the layer has a negligible effect on the growing modes. However, perturbations with wavelength comparable to layer's thickness are significantly affected by the thickness of the layer. We show that the thickness of the layer has a stabilizing effect on the two dominant growing modes. Transition between the modes not only depends on the magnetic strength, but also on the thickness of the layer.