Behavior of focus patterns in low Prandtl number convection

Journal Article · Mon Apr 04 00:00:00 EDT 1994 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.72.2191· OSTI ID:5073023

Hu, Y; Ecke, R E; Ahlers, G ^[1]

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1. Materials Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) Department of Physics and Center for Nonlinear Science, University of California-Santa Barbara, Santa Barbara, California 93106 (United States)

We present experimental results on the dynamics of concentric roll and textured patterns in a convecting fluid of Prandtl number about 1 and with radius-to-height ratio near 40 and for [epsilon]==[Delta][ital T]/[Delta][ital T][sub [ital c]][minus]1[le]0.8. At [epsilon]=0.21, the concentric-roll state was lost by the pattern center moving to the wall while nucleating new rolls which traveled outward. The textured pattern contained sidewall foci which also emitted traveling waves. The average frequency of the emission increased linearly with [epsilon], but then increased rapidly by about 40% at [epsilon][approx]0.65 where spiral defects appeared.

• OSTI ID: 5073023
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 72:14; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CONVECTION
ENERGY TRANSFER
FLUIDS
HEAT TRANSFER
MASS TRANSFER
NUCLEATION
PATTERN RECOGNITION
PRANDTL NUMBER
TEXTURE
TRAVELLING WAVES
VORTICES