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We numerically investigate both single and multiple droplet dissolution with droplets consisting of lighter liquid dissolving in a denser host liquid. The significance of buoyancy is quantified by the Rayleigh number Ra which is the…

Fluid Dynamics · Physics 2020-04-22 Kai Leong Chong , Yanshen Li , Chong Shen Ng , Roberto Verzicco , Detlef Lohse

Recent findings suggest that wall-bounded turbulent flow can take different statistically stationary turbulent states, with different transport properties, even for the very same values of the control parameters. What state the system takes…

Fluid Dynamics · Physics 2020-08-19 Qi Wang , Roberto Verzicco , Detlef Lohse , Olga Shishkina

Measurements of the Nusselt number $Nu$ and of temperature variations $\Delta T_b$ in the bulk fluid are reported for turbulent Rayleigh-B\'enard convection of a cylindrical sample. They cover the Rayleigh-number range $10^{9} \alt Ra \alt…

Fluid Dynamics · Physics 2009-04-17 Denis Funfschilling , Eberhard Bodenschatz , Guenter Ahlers

We study the evolution of a melting front between the solid and liquid phases of a pure incompressible material where fluid motions are driven by unstable temperature gradients. In a plane layer geometry, this can be seen as classical…

Fluid Dynamics · Physics 2019-01-15 Benjamin Favier , Jhaswantsing Purseed , Laurent Duchemin

Rayleigh-Benard convection and Taylor-Couette flow are two canonical flows that have many properties in common. We here compare the two flows in detail for parameter values where the Nusselt numbers, i.e. the thermal transport and the…

Fluid Dynamics · Physics 2017-04-12 Hannes Brauckmann , Bruno Eckhardt , Joerg Schumacher

Numerical data for the heat transfer as a function of the Prandtl (Pr) and Rossby (Ro) numbers in turbulent rotating Rayleigh-Benard convection are presented for Rayleigh number Ra = 10^8. When Ro is fixed the heat transfer enhancement with…

Fluid Dynamics · Physics 2011-12-05 Richard J. A. M. Stevens , Herman J. H. Clercx , Detlef Lohse

Turbulent thermal convection is characterized by the formation of large-scale structures and strong spatial inhomogeneity. This work addresses the relative heat transport contributions of the large-scale plume ejecting versus plume…

Fluid Dynamics · Physics 2021-04-09 Philipp Reiter , Olga Shishkina , Detlef Lohse , Dominik Krug

For two-dimensional Rayleigh-B\'{e}nard convection, classes of unstable, steady solutions were previously computed using numerical continuation (Waleffe, 2015; Sondak, 2015). The `primary' steady solution bifurcates from the conduction…

Fluid Dynamics · Physics 2021-01-20 Parvathi Kooloth , David Sondak , Leslie M. Smith

Planetary and stellar convection, which are compressible and turbulent, remain poorly understood. In this paper, we report numerical results on the scaling of Nusselt number ($\mathrm{Nu}$) and Reynolds number ($\mathrm{Re}$) for extreme…

Fluid Dynamics · Physics 2025-02-06 Harshit Tiwari , Mahendra K. Verma

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

We consider the two-dimensional Rayeigh-B\'enard convection problem between Navier-slip fixed-temperature boundary conditions and present a new upper bound for the Nusselt number. The result, based on a localization principle for the…

Analysis of PDEs · Mathematics 2024-10-29 Fabian Bleitner , Camilla Nobili

We perform direct numerical simulations of natural convection in a differentially heated cavity over Rayleigh number $Ra=10^6$--$10^8$ at Prandtl number $Pr=0.7$, systematically varying the aspect ratio over $0.1 \leq \Gamma \leq 60$.…

Fluid Dynamics · Physics 2026-05-06 Krishan Chand , Michael Quan , Haoxiang Luo

The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal…

Chaotic Dynamics · Physics 2009-11-10 Francisco Fontenele Araujo , S. Grossmann , D. Lohse

We perform the linear stability analysis and direct numerical simulations to study the effect of radius ratio on the instability and flow characteristics of the sheared annular centrifugal Rayleigh-B\'enard convection (ACRBC), where the…

Fluid Dynamics · Physics 2024-11-20 Jun Zhong , Junyi Li , Chao Sun

The variational multiscale (VMS) formulation is used to develop residual-based VMS large eddy simulation (LES) models for Rayleigh-B\'{e}nard convection. The resulting model is a mixed model that incorporates the VMS model and an eddy…

Computational Physics · Physics 2020-05-21 David Sondak , Thomas M. Smith , Roger P. Pawlowski , Sidafa Conde , John N. Shadid

Measurements of heat transport, as expressed by the Nusselt number $Nu$, are reported for turbulent Rayleigh-B\'enard convection of water containing up to 120 ppm by weight of poly-[ethylene oxide] with a molecular weight of $4\times10^6$…

Fluid Dynamics · Physics 2015-05-14 Guenter Ahlers , Alexei Nikolaenko

Using direct numerical simulations of Rayleigh-B\'{e}nard convection (RBC) under free-slip boundary condition, we show that the normalized correlation function between the vertical velocity field and the temperature field, as well as the…

Fluid Dynamics · Physics 2012-01-20 Mahendra K. Verma , Pankaj K. Mishra , Ambrish Pandey , Supriyo Paul

We studied flow organization and heat transfer properties in mixed turbulent convection within Poiseuille-Rayleigh-B\'enard channels subjected to temporally modulated sinusoidal wall temperatures. Three-dimensional direct numerical…

Fluid Dynamics · Physics 2025-03-12 Ao Xu , Rui-Qi Li , Heng-Dong Xi

We report pore-scale statistical properties of temperature and thermal energy dissipation rate in a two-dimensional porous Rayleigh-B\'enard (RB) cell. High-resolution direct numerical simulations were carried out for the fixed Rayleigh…

Fluid Dynamics · Physics 2023-09-20 Ao Xu , Ben-Rui Xu , Heng-Dong Xi

The heat transfer mechanism in Rayleigh-Benard convection in a liquid with a mean temperature close to its boiling point is studied through numerical simulations with point-like vapor bubbles, which are allowed to grow or shrink through…

Fluid Dynamics · Physics 2015-05-13 Paolo Oresta , Roberto Verzicco , Detlef Lohse , Andrea Prosperetti
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