The effect of Prandtl number on mixing in low Reynolds number Kelvin-Helmholtz billows
نویسندگان
چکیده
منابع مشابه
Prandtl number effects on mixing in Kelvin-Helmholtz billows
We use DNS to study the effect of Prandtl number on mixing in weakly density stratified Kelvin-Helmholtz (KH) billows at low to moderate Reynolds numbers. The time evolution of the density field of the flow and the mixing are significantly influenced by the Prandtl number. By increasing the Prandtl number, the final amount of mixing increases for Reynolds that are too low to sustain three-dimen...
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Mixing resulting from Kelvin-Helmholtz instability is studied by direct numerical simulations for an intermediate Reynolds number in stratified flows where vortex pairing occurs. We investigate how the interaction of several billows changes the mixing properties. Simulations in a long domain show that only considering the interaction of two billows overestimates the amount of mixing and mixing ...
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Direct numerical simulations are used to compare turbulent diffusivities of heat and salt during the growth and collapse of Kelvin–Helmholtz billows. The ratio of diffusivities is obtained as a function of buoyancy Reynolds number Reb and of the density ratio R (the ratio of the contributions of heat and salt to the density stratification). The diffusivity ratio is generally less than unity (he...
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We present experimental results for the Reynolds number ReU based on the horizontal mean-flow velocity U and for ReV based on the root-mean-square horizontal fluctuation velocity V for turbulent Rayleigh–Bénard convection in a cylindrical sample of aspect ratio Γ = 10.9 over the Prandtl number range 0.18 6 Pr 6 0.88. The results were derived from space–time cross-correlation functions of shadow...
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A train of Kelvin–Helmholtz billows in a deep stratiform cloud over a mountain range is documented using data from a high-resolution vertically pointing airborne Doppler radar. The billows had a spacing of 2–2.5 km and a small aspect ratio. The formation and decay of the billows appear to be related to flow acceleration over a mountain.
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ژورنال
عنوان ژورنال: Physics of Fluids
سال: 2016
ISSN: 1070-6631,1089-7666
DOI: 10.1063/1.4949267