A 2D numerical simulation program is developed for nonlinear evolution of magneto-Rayleigh-Taylor instability(MRTI). Based on an ideal magnetohydrodynamic model, a 5th WENO scheme is employed to calculate MHD equations and a projection scheme is used to clean spurious magnetic field divergence. The method is validated with MRTI compared with theory of linear stability. It is shown that the vertical magnetic field suppresses evidently MRTI in both linear and nonlinear stages. The parallel magnetic field has weak effect on MRTI in linear stage. However, it reduces remarkably Kelvin-Helmholtz instability and overall instability in nonlinear regime. High order harmonic occurs in the nonlinear evolution of single mode, and many modes except fundamental modes and harmonic occur in the evolution of double modes. In MRT evolution of multi-mode seeds inverse cascade occur, which means that perturbations evolve from short wavelength to long wavelength in the nonlinear stage.

A method that decreases useless magnetism pressure to amplify the power of MFCG(magnetic flux compression generator) is proposed, in which the charging loop is cut off after initial current is provided.By code MFCG(V),the simulation demonstrates effectiveness of the method.

A simple model for DNA molecules is proposed.The dynamical mechanism of the nonlinear localized excitation is studied by Runge-Kutta method.The large amplitude motion is simulated for N coupling base pairs of DNA molecules.The physical picture of the nonlinear localized excitation and its stable propagation can be emerged by means of adopting suitable parameters of Hamiltonian and time stpe.The nonlinear interaction on the beather effect is also discussed.