Stochastic Lorenz model for periodically driven Rayleigh-Bénard convection

OMAR OSENDA, CARLOS B. BRIOZZO, AND MANUEL O. CÁCERES

PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS

Año: 1997 vol. 55 p. 3824 - 3827

1063-651X

The order-disorder transition observed in periodically driven Rayleigh-Bénard convection is studied by extending the generalized Lorenz model introduced by Ahlers, Hohenberg, and Lücke [Phys. Rev. A 32, 3493 (1985)] to include the effects of thermal noise. It is shown that this stochastic Lorenz model predicts, for thermal noise intensities, an order-disorder transition line much closer to the experimental values than the prediction of previous models. This result makes clear that a dynamical description allowing for inertial effects is needed to account for the behavior of systems dynamically forced to cross an instability threshold.