Kelvin–Helmholtz billows above Richardson number
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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Dropsondes from the NOAA G-IV aircraft were used to examine the presence of low bulk Richardson numbers RB in tropical cyclones. At least one 400-m layer above z 5 7.5 km exhibited RB , 1 in 96% of the sondes andRB# 0.25 in 35%of the sondes. The latter represent almost certain turbulence. Sondes frommajor Hurricane Ivan (2004) were examined in detail. Turbulent layers fell into three broad grou...
متن کاملOn the critical Richardson number in stably stratified turbulence
Boris Galperin,1* Semion Sukoriansky2 and Philip S. Anderson3 1College of Marine Science, University of South Florida, St. Petersburg, Florida 33701, USA 2Department of Mechanical Engineering/Perlstone Center for Aeronautical Engineering Studies, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel 3Antarctic Climate and the Earth System Programme, British Antarctic Survey, Cambridge CB...
متن کاملDifferential Diffusion in Breaking Kelvin–Helmholtz Billows
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...
متن کاملVertically pointing airborne Doppler radar observations of Kelvin-Helmholtz billows
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: Journal of Fluid Mechanics
سال: 2019
ISSN: 0022-1120,1469-7645
DOI: 10.1017/jfm.2019.725