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Flow reversals in thermally driven turbulence

WebNov 10, 2024 · Here, α, ν, and k are the thermal expansion coefficient, kinematic viscosity, and thermal diffusivity of the fluid, respectively; Δ is the temperature difference across the fluid layer of height H; and g is the gravitational acceleration. Pervious studies 7–9 7. R. H. Kraichnan, “ Turbulent thermal convection at arbitrary Prandtl number,” Phys. Fluids 5, … WebApr 24, 2024 · Turbulent Rayleigh-Bénard convection in a square cavity with rough horizontal walls is investigated at a fixed Prandtl number Pr = 0.7 over the Rayleigh number range of 10 6 ≤ Ra ≤ 10 9.We have proposed five models with rough elements of the same height but different spatial distributions to evaluate their influences on the heat transport …

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WebSpontaneous and stochastic reversal of large scale flow structure is an intriguing and crucial phenomenon in turbulent Rayleigh-Bénard type natural convection. This paper proposes a new control approach to eliminate the reversals through stabilising the corner flows using two small sidewall controllers. WebSpontaneous and stochastic reversal of large scale flow structure is an intriguing and crucial phenomenon in turbulent Rayleigh-Bénard type natural convection. This paper … clayton village apartments https://prodenpex.com

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WebDec 26, 2024 · Abstract and Figures. In this combined experimental and numerical study on thermally driven turbulence in a rectangular cell, the global heat transport and the coherent flow structures are ... WebEddy (fluid dynamics) A vortex street around a cylinder. This can occur around cylinders and spheres, for any fluid, cylinder size and fluid speed, provided that the flow has a Reynolds number in the range ~40 to … WebJul 7, 2024 · We present an overview of the most relevant, and sometimes contrasting, theoretical approaches to Rayleigh–Taylor and mean-gradient-forced Rayleigh–Bénard two-dimensional turbulence together with numerical and experimental evidences for their support. The main aim of this overview is to emphasize that, despite the different … clayton wade williams

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Flow reversals in thermally driven turbulence

Phenomenology of buoyancy-driven turbulence: recent results

WebSep 30, 2011 · These corner flow rolls play a crucial role for the large scale wind reversal: They grow in kinetic energy and thus also in size thanks to plume detachments from the boundary layers up to the time that they take over the main, large scale diagonal flow, thus leading to reversal. WebApr 1, 1993 · @article{osti_6553407, title = {Thermally driven winds}, author = {Whiteman, C D}, abstractNote = {This presentation will summarize the present state of knowledge on slope and valley wind systems, emphasizing physical concepts and recent gains in understanding from observational programs in various parts of the world. The …

Flow reversals in thermally driven turbulence

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WebRole of flow reversals in transition to turbulence and relaminarization of pulsatile flows - Volume 917 ... A piston driven by a programmable DC servo motor was used to set-up a … WebWe analyze the reversals of the large-scale flow in Rayleigh-Bénard convection both through particle image velocimetry flow visualization and direct numerical simulations of …

Web•Dynamically driven flowsproduced by the interaction of the large-scale flow with topography •Thermally driven flows(a.k.a. diurnal mountain winds) produced by horizontal contrasts in heating and cooling that arise from topographic and land-surface contrasts •Frequently combined to some extent This Lecture Thermally Driven Mountain Winds WebFeb 27, 2024 · The phenomenology of RBC should apply to other flows where the buoyancy feeds the kinetic energy, e.g. bubbly turbulence and fully-developed Rayleigh Taylor instability. This paper also covers several models that predict the Reynolds and Nusselt numbers of RBC.

WebApr 18, 2024 · For buoyancy-driven turbulence with stable stratification, ... We, however, remark that the recent thermal convection simulations in a cube [57,58] exhibit flow reversals for a set of parameters. Hence, we … WebPDF - We analyze the reversals of the large-scale flow in Rayleigh-Benard convection both through particle image velocimetry flow visualization and direct numerical simulations of …

WebFlow Reversals in Thermally Driven Turbulence Kazuyasu Sugiyama, 1,3 Rui Ni, 2 Richard J.A.M. Stevens, 1 Tak Shing Chan, 1,2 Sheng-Qi Zhou, 2 Heng-Dong Xi, 2 …

WebJan 9, 2024 · Thermal effects Turbulent flows Heat transfer Navier Stokes equations Natural convection Thermal diffusivity ABSTRACT Direct numerical simulation (DNS) of non-slip two dimensional (2D) Rayleigh–Benard convection (RBC) is conducted for a wide range of Rayleigh number ( Ra up to 10 13) at Prandtl number Pr = 0.7 and aspect ratio … downspout mounting bracketsWebJul 1, 2011 · We observe large-scale circulation in the form of an ellipse with counter-rotating corner rolls in a classical square RB convection enclosure for Ra ¼ 10 8 and Pr … clayton wagonWebJun 1, 2024 · We describe the spectral theory including energy flux and show that the thermally-driven turbulence is similar to hydrodynamic turbulence. We also describe large-scale quantities like... downspout mouthWebJul 16, 2010 · Flow reversals in thermally driven turbulence Phys Rev Lett. 2010 Jul 16;105(3) :034503. doi ... We analyze the reversals of the large-scale flow in Rayleigh … clayton wallerWebWe analyze the reversals of the large-scale flow in Rayleigh-Bénard convection both through particle image velocimetry flow visualization and direct numerical simulations of the underlying Boussinesq equations in a (quasi-) two-dimensional, rectangular geometry of aspect ratio 1. For medium Prandtl number there is a diagonal large-scale convection roll … downspout mount for ring cameraWeb2 days ago · It is found that the flow reversal can be promoted at a Rayleigh number around 10⁷. ... We describe the spectral theory including energy flux and show that the thermally-driven turbulence is ... clayton wakemedWebSep 16, 2016 · Emergence of substructures inside the large-scale circulation induces transition in flow reversals in turbulent thermal convection. Journal of Fluid Mechanics, … downspout mounting hardware