摘要
The pinch instability for a cylindrical jet of liquid metal passed through by an axial electrical current is investigated. Besides the pinch effect originating from surface tension, the Lorentz force, created by the axial current density and the corresponding azimuthal magnetic field, causes an electromagnetic pinch effect. This effect has drawn attention in electrical engineering, because it can be used in the construction of liquid metal current limit- ers with self-healing properties. In this paper a simple model is derived using the shallow water approximation： the equations describing the full system are reduced to two one-dimensional evolution equations for the axial velocity and the radius of the jet. A stability analysis for this reduced system is carried out yielding critical current density and the growth rate for the instability. To investigate the nonlinear behaviour of the pinch instability for finite perturbations simulations, the shallow water model are performed.
基金
the Deutsche Forschungsgemeinschaft in the French-German DFG-CNRS research program 'Numerische Strmungssimulation-Simulation Numérique d'Ecoulements'
National Nataral Science Foundation of China under granted number 10772044
