High rayleigh number convection
WebSep 1, 1990 · The heat flux (Nusselt number) as a function of Rayleigh number, N Nu ≊0.3 N 2/7 Ra, is deduced from the presence of a mean flow and the nesting of the thermal boundary layer within the viscous one. The numerical coefficients are obtained from those known empirically for turbulent boundary layers. WebKeywords: mantle convection, high Rayleigh number, infinite Prandtl number, Nusselt number, spherical shell 1. Introduction The physical and chemical phenomena occurring on the surface and in the interior of the Earth are mainly con-trolled by the convective motion in the mantle. Mantle convection has many complex aspects, such as internal
High rayleigh number convection
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WebThe critical Rayleigh number for onset a layer with stress-free boundaries (appropriate for the surface and for the core-mantle interface) ... For high-Pr fluids, isoviscous convection has been studied for Ra up to 10 9, which includes the range of values estimated for the mantle (10 6 –10 8). WebNov 1, 2016 · Turbulent Rayleigh–Bénard convection in cubic cells is studied experimentally using two similar but not identical experimental setups in different laboratories. Both …
WebAug 1, 2024 · The Rayleigh number is set to 3 × 10 11 based on the temperature difference between the hot and cold surfaces. The simulation is initialized with water at rest, and turbulent convection occurs and is driven by the density difference caused by the temperature difference as the simulated time advances. WebNov 28, 2003 · These will include topics such as critical Rayleigh number for onset of bulk motion, flow patterns in laminar Rayleigh-B enard convection, measurement of heat …
WebAn experimental study of high Rayleigh number natural convection with internal heat sources has been conducted in a horizontal fluid layer with an insulated lower boundary and a constant-temperature upper boundary. Average heat transfer coefficients at the upper surface were obtained for Rayleigh numbers up to 2.17 x 10/sup 12/. WebNov 1, 2016 · At low Rayleigh number, the potential energy decreases, and the onset of convection is delayed when radiation is taken into account. However, once convection …
WebJun 4, 1998 · Thermal plumes in Rayleigh–Bénard convection have been observed to occur with strong vertical component of vorticity, resulting in spiraling hot updrafts and cold downdrafts. Results from two different simulations at Rayleigh numbers 9800 and 33 000 times the critical Rayleigh number close to the boundaries show rapid increase in the …
WebRayleigh number is defined as the product of grashof number and Prandtl number. The rayleigh number is denoted by the symbol Ra. As per the definition of rayleigh number, Ra = Gr × Pr Where equation for the grashof number is, Gr = ρ2gL3βΔT μ2 G r = ρ 2 g L 3 β Δ T μ 2 And the equation for the Prandtl number is, P r = μCp K P r = μ C p K soft tissue swelling elbow icd 10WebRecent Developments in Rayleigh-Bénard Convection Eberhard Bodenschatz, Werner Pesch, and Guenter Ahlers Annual Review of Fluid Mechanics Small-Scale Properties of Turbulent … soft tissue swelling in armpitWebJul 1, 1996 · A Rayleigh–Bénard cell has been designed to explore the Prandtl (Pr) dependence of turbulent convection in the cross-over range 0.7<21 and for the full … slow cooker tandoori chickenWebMay 10, 2001 · We study natural thermal convection of a fluid (corn syrup) with a large Prandtl number (103–107) and temperature-dependent viscosity. The experimental tank (1 × 1 × 0.3m) is heated from below with insulating top and side boundaries, so that the fluid experiences secular heating as experiments proceed. This setup allows a focused study … soft-tissue swelling around the left eyeWebMay 30, 2012 · Well-resolved direct numerical simulations of 2D Rayleigh-Bénard convection in a porous medium are presented for Rayleigh numbers Ra≤4×104which reveal that, … slow cooker takealotWebMar 1, 2015 · An experimental study of thermal convection in a porous medium investigates the heat transfer across a horizontal layer heated from below at high Rayleigh number. Using a packed bed of polypropylene spheres in a cubic enclosure saturated with compressed argon, the pressure was varied between 5.6 bar and 77 bar to obtain fluid … soft tissue swelling in jawWebOct 15, 2024 · The multi-phase Rayleigh–Bènard convection has been weakly investigated, even though it plays a leading role in the theoretical and applied physics of the heat transfer enhancement. For the case of moderate turbulent convection, a rather unexpected result is an unusual kind of wind reversal, in the sense that the fluid is found to be strongly … slow cooker tandoori chicken recipe