WAVELENGTH COMPETITION IN CONVECTIVE SYSTEMS

We investigate wavelength competition in two-dimensional pattern-formi ng systems with uniaxial anisotropy. A spatially periodic modulation o f the external driving force leads to an interplay with the wave lengt h of convection rolls which is similar to competing interactions betwe en two equilibrium lattice constants in adsorption problems. For a cla ss of anisotropic systems we find new types of stable patterns which a re induced by such wavelength competition. These are the skewed varico se pattern, an undulatory pattern and an incommensurate undulatory pat tern. Each of them seems observable in experiments on electroconvectio n and Rayleigh-Benard convection in nematic liquid crystals.