
Accession Number : AD0716530
Title : Theory of Nonlinear Waves.
Descriptive Note : Scientific rept.,
Corporate Author : INNSBRUCK UNIV (AUSTRIA) INST FOR THEORETICAL PHYSICS
Personal Author(s) : Schmid,Joachim M.
Report Date : 15 OCT 1970
Pagination or Media Count : 39
Abstract : The paper is a review of papers which handle nonlinear waves with an averaging technic developed by Whitham. If it is possible to derive the differential equations governing the problem from a variational principle the Lagrangian can be averaged over one period. From the averaged Lagrangian averaged conservation equations are derived and from these one finds a second order differential equation in terms of frequency, wavenumber and amplitude  that is a dispersion equation. Besides the frequency dispersion an amplitude dispersion occurs too. The distortion of the waveform depends on whether the Dispersion equation is elliptic or hyperbolic. The nonlinearity may produce phase jumps and discontinuities of the wavenumber. (Author)
Descriptors : (*PARTIAL DIFFERENTIAL EQUATIONS, WAVE PROPAGATION), (*NONLINEAR DIFFERENTIAL EQUATIONS, NUMERICAL INTEGRATION), DISPERSION RELATIONS, INTEGRALS, APPROXIMATION(MATHEMATICS), POWER SERIES, WAVE FUNCTIONS, AUSTRIA
Subject Categories : Numerical Mathematics
Distribution Statement : APPROVED FOR PUBLIC RELEASE