Zusammenfassung
A method is described for calculating nonlinear steady-state patterns in channels
taking into account the effect of an end wall across the channel. The key feature
is the determination of the phase shift of the nonlinear periodic form distant from
the end wall as a function of wavelength. This is found by analysing the solution
close to the end wall, where Floquet theory is used to describe the departure of the
solution from its periodic form and to locate the Eckhaus stability boundary. A
restricted band of wavelengths is identified, within which solutions for the phase
shift are found by numerical computation in the fully nonlinear regime and by
asymptotic analysis in the weakly nonlinear regime. Results are presented here
for the two-dimensional Swift-Hohenberg equation but in principle the method can
be applied to more general pattern-forming systems. Near onset, it is shown that
for channel widths less than a certain critical value the restricted band includes
both subcritical and supercritical wavelengths, whereas for wider channels only
subcritical wavelengths are allowed.
Key words: convection; nonlinear systems; pattern selection.
Nutzer