Nonlinear Kelvin–Helmholtz instability of a subsonic gas–liquid interface in the presence of a normal magnetic field

The nonlinear Kelvin–Helmholtz instability of a horizontal interface between a magnetic inviscid incompressible liquid and an inviscid laminar subsonic magnetic gas is investigated in the presence of a normal magnetic field. The gas and the liquid are assumed to have finite thicknesses. The stability of the progressive waves is discussed theoretically. The stability diagrams are discussed using a numerical application. The solitons, at some interval of the interface, are discussed. The stability conditions near the cutoff magnetic field is taken into account.