Abstract
Shadowgraph flow-visualization studies and heat-flux measurements were used to study convection subjected to temporal modulation of the Rayleigh number in the form , where is the unmodulated threshold, and and are scaled by the vertical thermal diffusion time. For and the predicted hexagonal patterns were observed for a range of immediately above the convective threshold . With increasing there is a region exhibiting coexistence between hexagons and rolls, followed by roll-like patterns. The observed boundaries between these regions and the magnitude of the convective heat transport are consistent with theory.
- Received 31 May 1988
DOI:https://doi.org/10.1103/PhysRevLett.61.947
©1988 American Physical Society