Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/24896
Title: Cavity flow induced by a fluctuating acceleration field
Author: Thomson, J. Ross
Casademunt i Viader, Jaume
Viñals Giménez, Jorge
Keywords: Creixement cristal·lí
Ambients de microgravetat
Ciència dels materials
Semiconductors
Mecànica de fluids
Crystal growth
Reduced gravity environments
Materials science
Semiconductors
Fluid mechanics
Issue Date: Feb-1995
Publisher: American Institute of Physics
Abstract: Buoyancy driven convection induced by a fluctuating acceleration field is studied in a two dimensional square cavity. This is a simplified model of, for example, fluid flow in a directional solidification cell subject to external accelerations, such as those encountered in a typical microgravity environment (g‐jitter). The effect of both deterministic and stochastic acceleration modulations normal to the initial density gradient are considered. In the latter case, the acceleration field is modeled by narrow band noise defined by a characteristic frequency Ω, a correlation time τ, and an intensity G2. If the fluid is quiescent at t=0 when the acceleration field is initiated, the ensemble average of the vorticity at the center of the cavity remains zero for all times. The mean squared vorticity 〈ξ2〉, however, is seen to exhibit two distinct regimes: For t≪τ, 〈ξ2〉 oscillates in time with frequency Ω. For t≫τ, 〈ξ2〉 grows linearly in time with an amplitude equal to R2Pr/(1+(Ωτ))2, where R is a new dimensionles...
Note: Reproducció del document publicat a: http://doi.org/10.1063/1.868627
It is part of: Physics of Fluids, 1995, vol. 7, num. 2, p. 292-301
Related resource: http://doi.org/10.1063/1.868627
URI: http://hdl.handle.net/2445/24896
ISSN: 0021-8979
Appears in Collections:Articles publicats en revistes (Física Quàntica i Astrofísica)

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