Kelvin–Helmholtz instability in sheared dusty plasma flows including dust polarization and ion drag forces

Abstract

Velocity shear driven Kelvin–Helmholtz (K-H) instability has been investigated in an incompressible subsonic sheared dusty plasma with ion drag and dust polarization forces. A three-component dusty fluid model has been formulated in connection with thermal electrons, inertial ions and charged dust grains. Dispersion relation of K-H instability along with dust-ion two-stream instability has been analyzed for a typical astrophysical dusty plasma environment. The magnitude of the polarization force is found to be small compared to the other forces, although it significantly modifies the K-H modes. The simultaneous presence of ion drag and dust polarization forces excites the K-H instability, which in the absence of these forces, is completely suppressed. It is also observed that the dust polarization interaction parameter and the magnitude of the shear velocity increase the growth rate of the K-H instability. The present results can have significant relevance in understanding the development of velocity shear driven K-H instability in some molecular outflows [1], Saturn’s rings [2] etc.