Simulations of oscillatory convection in 3He-4He mixtures in moderate aspect ratio containers -: art. no. 064102

Simulations of He-3-He-4 mixtures with negative separation ratios in two-dimensional containers with realistic boundary conditions and moderately large aspect ratio Gamma are described. The system exhibits a large variety of states with complex time dependence including intermittent wave localization and chaotic "repeated transients." Steady but localized states are also found. Particular attention is paid to the transitions that occur for (R-R-c)/R(c)approximate to Gamma(-2), where R is the Rayleigh number and R-c its critical value for the primary instability, in order to clarify the gradual transition from a small number of active degrees of freedom [(R-R-c)/R-c<<Gamma(-2)] to many active degrees of freedom [(R-R-c)/R-c>>Gamma(-2)]. (c) 2005 American Institute of Physics.