摘要：We study the linear stability of two superposed layers of viscous, immiscible fluids of different densities. The whole system is subject to horizontal quasi-periodic oscillation with two incommensurates frequencies ω1and ω2. The spectral method and Floquet’s theory combined with Runge-Kutta method are used to solve numericelly the linear problem. We analyse the influence of the frequencies ratio$ \omega = {{{\omega _1}} \over {{\omega _2}}} $, on the mariginal stability. The numerical solution shows that the quasi-periodic excitation has a stabilizing or a destabilizing effect on the Kelvin-Helmholtz instability as well as in the parametric resonances depending on the frequency ratio and the amplitudes ratio$ \alpha = {{{\alpha _2}} \over {{\alpha _1}}} $.
关键词：enLinear stabilityquasi-periodic oscillationRunge-KuttaFloquet’s theoryinstability of Kelvin-Helmholtzparametric resonance.
