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Related papers: Universal Relation between Nusselt Number and Beja…

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This study derives a scaling law connecting the Nusselt (Nu) and Bejan (Be) numbers in natural convection. Combining entropy generation analysis with boundary-layer scaling, the relation Be^-1 - 1 = a Nu^b naturally emerges without explicit…

Fluid Dynamics · Physics 2026-04-28 Takuya Masuda , Toshio Tagawa

The emergence of unified constitutive law is a hallmark of convective turbulence, i.e., $Nu \sim Ra^\beta$ with $\beta \approx 0.3$ in the classical and $\beta=1/2$ in the ultimate regime, where the Nusselt number $Nu$ measures the global…

Fluid Dynamics · Physics 2023-12-14 Ze-Lin Huang , Jian-Zhao Wu , Xi-Li Guo , Chao-Ben Zhao , Bo-Fu Wang , Kai Leong Chong , Quan Zhou

We study numerically the dependence of heat transport on the maximum velocity and shear rate of physical circulating flows, which are prescribed to have the key characteristics of the large-scale mean flow observed in turbulent convection.…

Chaotic Dynamics · Physics 2009-11-07 Emily S. C. Ching , K. M. Pang

A systematic theory for the scaling of the Nusselt number $Nu$ and of the Reynolds number $Re$ in strong Rayleigh-Benard convection is suggested and shown to be compatible with recent experiments. It assumes a coherent large scale…

chao-dyn · Physics 2017-05-17 Siegfried Grossmann , Detlef Lohse

New bounds are proven on the mean vertical convective heat transport, $\overline{\langle wT \rangle}$, for uniform internally heated (IH) convection in the limit of infinite Prandtl number. For fluid in a horizontally-periodic layer between…

Fluid Dynamics · Physics 2023-03-22 Ali Arslan , Giovanni Fantuzzi , John Craske , Andrew Wynn

Previous numerical studies on homogeneous Rayleigh-B\'enard convection, which is Rayleigh-B\'enard convection (RBC) without walls, and therefore without boundary layers, have revealed a scaling regime that is consistent with theoretical…

Fluid Dynamics · Physics 2018-06-22 Chong Shen Ng , Andrew Ooi , Detlef Lohse , Daniel Chung

Rigorous upper limits on the vertical heat transport in two dimensional Rayleigh-Benard convection between stress-free isothermal boundaries are derived from the Boussinesq approximation of the Navier-Stokes equations. The Nusselt number Nu…

Fluid Dynamics · Physics 2015-05-27 Jared P. Whitehead , Charles R. Doering

We calculate the scalar transport rate, as characterized by the Nusselt number\,($Nu$), from a neutrally buoyant spherical drop in an ambient linear flow, in the absence of inertia and in the strong convection limit. This corresponds to the…

Fluid Dynamics · Physics 2026-01-27 Sabarish V. Narayanan , Ganesh Subramanian

We present a theory to describe the Nusselt number ($Nu$), corresponding to the heat or mass flux, as a function of the Rayleigh--Darcy number ($Ra$), the ratio of buoyant driving force over diffusive dissipation, in convective porous media…

Fluid Dynamics · Physics 2024-11-20 Xiaojue Zhu , Yifeng Fu , Marco De Paoli

A fully non-dimensional correlation for the Nusselt number associated to cooling processes in vertical storage tanks under laminar natural convection is presented. The derived correlation depends on the average temperature and can be used…

Fluid Dynamics · Physics 2013-02-25 Rejane de Cesaro Oliveski , Fernando Haas

We prove a new rigorous upper bound on the vertical heat transport for B\'enard-Marangoni convection of a two- or three-dimensional fluid layer with infinite Prandtl number. Precisely, for Marangoni number $Ma \gg 1$ the Nusselt number $Nu$…

Fluid Dynamics · Physics 2020-01-01 Giovanni Fantuzzi , Camilla Nobili , Andrew Wynn

We study fully compressible convection in the context of plane-parallel, polytropically stratified atmospheres. We perform a suite of 2D and 3D simulations in which we vary the initial superadiabaticity ($\epsilon$) and the Rayleigh number…

Fluid Dynamics · Physics 2017-09-06 Evan H. Anders , Benjamin P. Brown

Gradient ascent methods are developed to compute incompressible flows that maximize heat transport between two isothermal no-slip parallel walls. Parameterizing the magnitude of velocity fields by a P\'eclet number $\text{Pe}$ proportional…

Fluid Dynamics · Physics 2020-04-13 Andre N. Souza , Ian Tobasco , Charles R. Doering

In this study we follow Grossmann and Lohse, Phys. Rev. Lett. 86 (2001), who derived various scalings regimes for the dependence of the Nusselt number $Nu$ and the Reynolds number $Re$ on the Rayleigh number $Ra$ and the Prandtl number…

Fluid Dynamics · Physics 2017-11-01 Olga Shishkina , Mohammad S. Emran , Siegfried Grossmann , Detlef Lohse

We present results on the effect of dispersed droplets in vertical natural convection (VC) using direct numerical simulations based on a two-way fully coupled Euler-Lagrange approach with a liquid phase and a dispersed droplets phase. For…

Fluid Dynamics · Physics 2019-11-20 Chong Shen Ng , Vamsi Spandan , Roberto Verzicco , Detlef Lohse

A solvable turbulent model is used to predict both the structure of the boundary layer and the scaling laws in thermal convection. The transport of heat depends on the interplay between the thermal, viscous and integral scales of…

Fluid Dynamics · Physics 2015-05-28 B. Dubrulle

We report on the transition between two regimes of heat transport in a radiatively driven convection experiment, where a fluid gets heated up within a tunable heating length $\ell$ in the vicinity of the bottom of the tank. The first regime…

Fluid Dynamics · Physics 2020-10-22 V. Bouillaut , S. Lepot , S. Aumaître , B. Gallet

We provide scaling relations for the Nusselt number $Nu$ and the friction coefficient $C_{S}$ in sheared Rayleigh-B\'enard convection, i.e., in Rayleigh-B\'enard flow with Couette or Poiseuille type shear forcing, by extending the Grossmann…

Laminar natural convection from two horizontally aligned isothermal cylinders in unconfined Power-law fluids has been investigated numerically. The effect of horizontal spacing (0<=(S/D)<=10) on both momentum and heat transfer…

Fluid Dynamics · Physics 2021-07-08 Subhasisa Rath , Sukanta K. Dash

Thermal convection driven by internal heat sources and sinks was recently shown experimentally to exhibit the mixing-length, or "ultimate", scaling-regime: the Nusselt number $Nu$ (dimensionless heat flux) increases as the square-root of…

Fluid Dynamics · Physics 2020-10-23 B. Miquel , S. Lepot , V. Bouillaut , B. Gallet
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