Abstract
The 13-mode Lorenz model previously introduced to describe hexagons and rolls in a Rayleigh-Bénard cell with periodic modulation of the lower plate is generalized to arbitrary time dependence of both upper and lower plates. Earlier results of Krishnamurti [J. Fluid Mech. 33, 445 (1968); 33, 457 (1968)] for the case of a linear ramp with constant temperature difference are recovered. The conditions for observing hexagons are derived analytically for periodic modulation with different frequencies, amplitudes, and phases at the two plates.
- Received 2 November 1988
DOI:https://doi.org/10.1103/PhysRevA.39.4132
©1989 American Physical Society