Stochastic Lorenz model for periodically driven Rayleigh-Benard convection

The order-disorder transition observed in periodically driven Rayleigh-Benard convection is studied by extending the generalized Lorenz model introduced by Ahlers, Hohenberg, and Lucke [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.