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A data-driven turbulence model for coarse-grained numerical simulations of two-dimensional Rayleigh-B\'enard convection is proposed. The model starts from high-fidelity data and is based on adjusting the Fourier coefficients of the…

Fluid Dynamics · Physics 2024-02-08 Sagy Ephrati , Paolo Cifani , Bernard Geurts

We perform a bifurcation analysis of the steady states of Rayleigh--B\'enard convection with no-slip boundary conditions in two dimensions using a numerical method called deflated continuation. By combining this method with an…

Fluid Dynamics · Physics 2022-05-19 Nicolas Boullé , Vassilios Dallas , Patrick E. Farrell

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

Turbulent Rayleigh-Benard convection with phase changes in an extended layer between two parallel impermeable planes is studied by means of three-dimensional direct numerical simulations for Rayleigh numbers between 10^4 and 1.5\times 10^7…

Fluid Dynamics · Physics 2012-07-27 Thomas Weidauer , Joerg Schumacher

The logarithmic law of mean temperature profile has been observed in different regions in Rayleigh-B\'enard turbulence. However, how thermal plumes correlate to the log law of temperature and how the velocity profile changes with pressure…

Fluid Dynamics · Physics 2019-10-08 Hong-Yue Zou , Wen-Feng Zhou , Xi Chen , Yun Bao , Jun Chen , Zhen-Su She

We present results from a numerical study of particle dispersion in the weakly nonlinear regime of Rayleigh-B\'enard convection of a fluid with Prandtl number around unity, where bi-stability between ideal straight convection rolls and weak…

Fluid Dynamics · Physics 2016-06-29 Simon Schütz , Eberhard Bodenschatz

We study, using direct numerical simulations, the effect of geometrical confinement on heat transport and flow structure in Rayleigh-B\'enard convection in fluids with different Prandtl numbers. Our simulations span over two decades of…

Fluid Dynamics · Physics 2017-09-22 Kai Leong Chong , Sebastian Wagner , Matthias Kaczorowski , Olga Shishkina , Ke-Qing Xia

Experimental and numerical data for the heat transfer as a function of the Rayleigh-, Prandtl-, and Rossby numbers in turbulent rotating Rayleigh-Benard convection are presented. For relatively small $Ra ~ 10^8$ and large Pr modest rotation…

Axisymmetric steady solutions of Taylor-Couette flow at high Taylor numbers are studied numerically and theoretically. As the axial period of the solution shortens from about one gap length, the Nusselt number goes through two peaks before…

Fluid Dynamics · Physics 2023-08-02 Kengo Deguchi

Asymptotically large Reynolds number hydrodynamic turbulence is characterized by multi-scaling of moments of velocity increments and spatial derivatives. With decreasing Reynolds number toward $R_{\lambda}=R^{tr}_{\lambda}\approx 9.0$, the…

Fluid Dynamics · Physics 2020-06-22 Victor Yakhot

Measurements of wall shear-stress fluctuations on very long timescales ($\ge$ 1900 free-fall time units) are reported for turbulent Rayleigh-Benard (RB) convection in air at the heated bottom plate of a RB cell, 2.5 m in diameter and 2.5 m…

Fluid Dynamics · Physics 2019-01-23 Christoph Bruecker , Ronald Du Puits

Quasi-static Rayleigh-B\'enard convection with an imposed horizontal magnetic field is investigated numerically for Chandrasekhar numbers up to $Q=10^6$ with stress free boundary conditions. Both $Q$ and the Rayleigh number ($Ra$) are…

Fluid Dynamics · Physics 2023-10-11 Michael A. Calkins , Talal AlRefae , Angel Hernandez , Ming Yan , Stefano Maffei

We investigate the large-scale circulation (LSC) of turbulent Rayleigh-B\'enard convection in a large box of aspect ratio $\Gamma =32$ for Rayleigh numbers up to $Ra=10^9$ and at a fixed Prandtl number $Pr=1$. A conditional averaging…

Rayleigh-B{\'e}nard convection is investigated with sulfur hexafluoride (SF$_6$) in the vicinity of its critical point. In the supercritical domain, direct measurements of the heat flux $Q$ as a function of the temperature difference…

Fluid Dynamics · Physics 2025-03-12 Valentin Mouet , Guillaume Michel , François Pétrélis , Stephan Fauve

Rayleigh-B\'enard convection is numerically simulated in two- and three-dimensions using a recently developed two-component lattice Boltzmann equation (LBE) method. The density field of the second component, which evolves according to the…

comp-gas · Physics 2016-08-31 Xiaowen Shan

We study the Rayleigh-B{\'e}nard convection in a 2-D rectangular domain with no-slip boundary conditions for the velocity. The main mathematical challenge is due to the no-slip boundary conditions, since the separation of variables for the…

Pattern Formation and Solitons · Physics 2013-02-18 Taylan Sengul , Jie Shen , Shouhong Wang

We investigate the origin of various convective patterns using bifurcation diagrams that are constructed using direct numerical simulations. We perform two-dimensional pseudospectral simulations for a Prandtl number 6.8 fluid that is…

Fluid Dynamics · Physics 2010-06-01 Supriyo Paul , Mahendra K. Verma , Pankaj Wahi , Sandeep K. Reddy , Krishna Kumar

Rotation, which stabilizes flow, can enhance the heat transfer in Rayleigh-B\'enard convection (RBC) through Ekman pumping. In this Letter, we present the results of our direct numerical simulations of rotating RBC, providing a…

Fluid Dynamics · Physics 2024-01-18 Mohammad Anas , Pranav Joshi

We prove the first rigorous bound on the heat transfer for three-dimensional Rayleigh-B\'enard convection of finite-Prandtl-number fluids between free-slip boundaries with an imposed heat flux. Using the auxiliary functional method with a…

Fluid Dynamics · Physics 2018-04-11 Giovanni Fantuzzi

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