Kelvin-Helmholtz instability in a compressible plasma with a magnetic field and velocity shear |
| |
| Affiliation: | 1. Institute of Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Athens, Greece;2. Bulgarian Academy of Sciences, Sofia, Bulgaria;3. Institute of Information and Communication Technologies, Bulgarian Academy of Sciences, Sofia, Bulgaria;1. Faculty of Education, Mus Alparslan University, 49250 Mus, Turkey;2. Independent researcher, Bingöl, Turkey;3. Department of Physics, Faculty of Science and Art, Mus Alparslan University, 49250 Mus, Turkey;1. CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India;2. Academy of Scientific and Innovative Research (AcSIR), CSIR-HRDC Campus, Postal Staff College Area, Sector 19, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh 201002, India;3. National Centre for Antarctic and Ocean Research, Head Land Sada, Vasco-da-Gama, Goa 403804, India;1. Research Focus Area for Chemical Resource Beneficiation, Catalysis and Synthesis Research Group, North-West University, Potchefstroom 2520, South Africa;2. Department of Process Engineering, Stellenbosch University, Stellenbosch 7602, South Africa |
| |
| Abstract: | The development of the Kelvin-Helmholtz instability (KHI) in a compressible plasma containing a magnetic field is studied for a finite thick layer with a velocity shear in a linear two-dimensional MHD approximation. Approximate analytical expressions for the phase speed, growth rate and wavenumber of the fastest growing unstable mode are derived for the velocity profile across the layer with the velocity shear having a sudden onset, termed a sharp elbow. The Dispersion equation is obtained from boundary conditions on the sharp elbow where the logarithmic derivative of the total pressure (or normal component of velocity) plays the main role.The KHI, driven by velocity shear, is considered as a possible generator of plasma oscillations in magnetospheric regions such as at the boundary between the inner plasma sheet and the plasmasphere, the boundary between the plasma sheet and the tail lobes and the boundary between the plasma sheet and the magnetopause. Analytical expressions for the phase speed, growth rate, period and wavenumber of the growing unstable mode obtained with some simplifying assumptions leads to values similar to the results of numerical analyses. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
