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相关论文: Predictions of Reynolds and Nusselt numbers in tur…

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In this paper, we extend Grossmann and Lohse's (GL) model [Phys. Rev. Lett. {\bf 86}, 3316 (2001)] for the predictions of Reynolds number (Re) and Nusselt number (Nu) in turbulent Rayleigh-B\'{e}nard convection (RBC). Towards this…

流体动力学 · 物理学 2021-01-12 Shashwat Bhattacharya , Mahendra K. Verma , Ravi Samtaney

We conduct direct numerical simulations for turbulent Rayleigh-B\'{e}nard (RB) convection, driven simultaneously by two scalar components (say, temperature and salt concentration) with different molecular diffusivities, and measure the…

流体动力学 · 物理学 2018-07-04 Yantao Yang , Roberto Verzicco , Detlef Lohse

The progress in our understanding of several aspects of turbulent Rayleigh-Benard convection is reviewed. The focus is on the question of how the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number…

流体动力学 · 物理学 2015-05-13 Guenter Ahlers , Siegfried Grossmann , Detlef Lohse

The behaviour of the turbulent Prandtl number ($Pr_t$) for buoyancy-affected flows near a vertical surface is investigated as an extension study of {Gibson \& Leslie, \emph{Int. Comm. Heat Mass Transfer}, Vol. 11, pp. 73-84 (1984)}. By…

流体动力学 · 物理学 2021-07-26 Xiaowei Xu , Andrew S. H. Ooi , Richard D. Sandberg

A modelling framework based on the resolvent analysis and machine learning is proposed to predict the turbulent energy in incompressible channel flows. In the framework, the optimal resolvent response modes are selected as the basis…

流体动力学 · 物理学 2024-03-11 Yitong Fan , Bo Chen , Weipeng Li

We numerically investigate turbulent Rayleigh-B\'enard convection within two immiscible fluid layers, aiming to understand how the layer thickness and fluid properties affect the heat transfer (characterized by the Nusselt number $Nu$) in…

流体动力学 · 物理学 2022-05-24 Hao-Ran Liu , Kai Leong Chong , Rui Yang , Roberto Verzicco , Detlef Lohse

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…

流体动力学 · 物理学 2025-02-06 Harshit Tiwari , Mahendra K. Verma

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 · 物理学 2017-05-17 Siegfried Grossmann , Detlef Lohse

A combined convolutional autoencoder-recurrent neural network machine learning model is presented to analyse and forecast the dynamics and low-order statistics of the local convective heat flux field in a two-dimensional turbulent…

流体动力学 · 物理学 2022-04-13 Sandeep Pandey , Philipp Teutsch , Patrick Mäder , Jörg Schumacher

The Rayleigh-Benard theory by Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)] is extended towards very large Prandtl numbers Pr. The Nusselt number Nu is found here to be independent of Pr. However, for fixed Rayleigh numbers Ra>…

混沌动力学 · 物理学 2009-10-31 Siegfried Grossmann , Detlef Lohse

In turbulent wall sheared thermal convection, there are three different flow regimes, depending on the relative relevance of thermal forcing and wall shear. In this paper we report the results of direct numerical simulations of such sheared…

流体动力学 · 物理学 2021-01-20 Alexander Blass , Pier Tabak , Roberto Verzicco , Richard J. A. M. Stevens , Detlef Lohse

The Reynolds-averaged Navier-Stokes (RANS) equations are widely used in turbulence applications. They require accurately modeling the anisotropic Reynolds stress tensor, for which traditional Reynolds stress closure models only yield…

流体动力学 · 物理学 2022-03-23 Haitz Sáez de Ocáriz Borde , David Sondak , Pavlos Protopapas

Simulation of turbulent flows at high Reynolds number is a computationally challenging task relevant to a large number of engineering and scientific applications in diverse fields such as climate science, aerodynamics, and combustion.…

Data-driven flow control has significant potential for industry, energy systems, and climate science. In this work, we study the effectiveness of Reinforcement Learning (RL) for reducing convective heat transfer in the 2D Rayleigh-B\'enard…

流体动力学 · 物理学 2025-09-01 Thorben Markmann , Michiel Straat , Sebastian Peitz , Barbara Hammer

The design of film cooling systems relies heavily on Reynolds-Averaged Navier-Stokes (RANS) simulations, which solve for mean quantities and model all turbulent scales. Most turbulent heat flux models, which are based on isotropic diffusion…

流体动力学 · 物理学 2019-10-09 Pedro M. Milani , Julia Ling , John K. Eaton

The present study represents a data-driven turbulent model with Galilean invariance preservation based on machine learning algorithm. The fully connected neural network (FCNN) and tensor basis neural network (TBNN) [Ling et al. (2016)] are…

流体动力学 · 物理学 2025-02-11 Xuepeng Fu , Shixiao Fu , Chang Liu , Mengmeng Zhang , Qihan Hu

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…

流体动力学 · 物理学 2015-05-28 B. Dubrulle

We propose a phenomenological model for thermal convection at high Rayleigh numbers. It hypothesizes existence of a high-Reynolds-number turbulent boundary layer near each horizontal plate, which is shown to be convective. The convective…

流体动力学 · 物理学 2024-03-27 Chenning Tong

The Reynolds-Averaged Navier-Stokes (RANS) approach remains a backbone for turbulence modeling due to its high cost-effectiveness. Its accuracy is largely based on a reliable Reynolds stress anisotropy tensor closure model. There has been…

流体动力学 · 物理学 2022-08-31 Jiayi Cai , Pierre-Emmanuel Angeli , Jean-Marc Martinez , Guillaume Damblin , Didier Lucor

A fully-convolutional neural-network model is used to predict the streamwise velocity fields at several wall-normal locations by taking as input the streamwise and spanwise wall-shear-stress planes in a turbulent open channel flow. The…

流体动力学 · 物理学 2020-08-26 L. Guastoni , M. P. Encinar , P. Schlatter , H. Azizpour , R. Vinuesa
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