ON THE EXISTENCE AND COMPUTATION OF PERIODIC TRAVELLING WAVES FOR A 2D WATER WAVE MODEL.

Autor: Quintero, José Raúl, Grajales, Juan Carlos Muñoz
Předmět:
Zdroj: Communications on Pure & Applied Analysis; Mar2018, Vol. 17 Issue 2, p557-N.PAG, 22p
Abstrakt: In this work we establish the existence of at least one weak periodic solution in the spatial directions of a nonlinear system of two coupled differential equations associated with a 2D Boussinesq model which describes the evolution of long water waves with small amplitude under the effect of surface tension. For wave speed 0<|c|<1, the problem is reduced to finding a minimum for the corresponding action integral over a closed convex subset of the space Hk¹(R) (k-periodic functions f∈Lk²(R) such that f′∈Lk²(R)). For wave speed |c|>1, the result is a direct consequence of the Lyapunov Center Theorem since the nonlinear system can be rewritten as a 4×4 system with a special Hamiltonian structure. In the case |c|>1, we also compute numerical approximations of these travelling waves by using a Fourier spectral discretization of the corresponding 1D travelling wave equations and a Newton-type iteration. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index