Article
Physics, Multidisciplinary
Felix Schindler, Sven Eckert, Till Zuerner, Joerg Schumacher, Tobias Vogt
Summary: In highly turbulent liquid metal convection experiments, the large-scale flow structure and the turbulent transfer of heat and momentum were directly measured. It was found that the aspect ratio has a significant impact on the scaling laws for heat and momentum transfer.
PHYSICAL REVIEW LETTERS
(2022)
Article
Thermodynamics
R. H. Hernandez, M. Vial
Summary: This study reports experimental results on inclined Rayleigh–Benard convection in a convection cell with moderate aspect ratio using a high Prandtl aqueous solution of glycerol. The aim is to measure the transition from convective to conductive regime by varying the tilt angle of the cell. Flow transitions between different flow patterns are observed by measuring changes in the heat transfer curve and visualizing the flow.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Mechanics
Shashwat Bhattacharya, Mahendra K. Verma, Arnab Bhattacharya
Summary: A multivariate regression model and a neural network model were developed in this paper to predict the Reynolds number and Nusselt number in turbulent thermal convection. By comparing with earlier models, it was found that the machine-learning models in this work provided the best match with the experimental and numerical results.
Article
Mechanics
Jian-Chao He, Yun Bao, Xi Chen
Summary: Direct numerical simulation (DNS) is conducted for non-slip two dimensional (2D) Rayleigh-Benard convection (RBC) with a wide range of Rayleigh number (Ra up to 10^13), Prandtl number Pr 1/4 0.7, and aspect ratio gamma= 1. The thermal dissipation rate shows an evident scaling transition at Ra asymptotic to 10^9. The mean temperature gradient in the thermal boundary layer is the dominant contribution to the transition. The Nusselt number also exhibits the transition at Ra asymptotic to 10^9. Rating: 7/10.
Article
Thermodynamics
Huilin Tong, Zhengyu Wang, Zhengdao Wang, Hui Yang, Yuehong Qian, Yikun Wei
Summary: The joint effect of rectangular-type roughness and horizontal vibration on two-dimensional turbulent Rayleigh-Benard convection is studied using the thermal lattice Boltzmann method. The Nusselt number and plume dynamics of the convection are the main focus, within the ranges of dimensionless vibration frequency 0≤ω*≤1000 and dimensionless roughness height 0≤h*≤0.05. Numerical results show that the Nusselt number is mostly proportional to the roughness height and exponentially related to the vibration frequency. Furthermore, heat transfer is enhanced by 3.06 times under the joint effect of horizontal vibration and rectangular roughness on turbulent Rayleigh-Benard convection. This provides important insights into the mechanism of cooperative heat transfer enhancement.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Mechanics
Sebastian Moller, Theo Kaeufer, Ambrish Pandey, Joerg Schumacher, Christian Cierpka
Summary: Turbulent superstructures in horizontally extended three-dimensional Rayleigh-Benard convection flows are investigated in controlled laboratory experiments in water at Prandtl number Pr = 7. The experimental results confirm that the superstructure patterns are an important backbone of the heat transfer.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Alessandro De Rosis, Giovanni Giustini
Summary: This paper analyzes the flow and heat transfer regimes in Rayleigh-Benard convection with a melting boundary using numerical simulations. The results provide insight into the complex behavior of thermal convection, melting, and fluid dynamics.
Article
Engineering, Mechanical
Jian-Zhao Wu, Bo-Fu Wang, Quan Zhou
Summary: In this study, direct numerical simulations of turbulent Rayleigh-Benard convection (RBC) were conducted with consideration of both roughness and external vibration. It was found that increasing the vibration frequency greatly enhances the heat transfer after exceeding a critical value, due to the destabilization of thermal boundary layers and the generation of more thermal plumes. Additionally, the vibration-induced heat transfer enhancement significantly affects the scaling behavior between heat flux and Rayleigh number.
ACTA MECHANICA SINICA
(2022)
Article
Thermodynamics
M. Delort-Laval, L. Soucasse, Ph Riviere, A. Soufiani
Summary: This paper investigates the impact of radiative transfer on Rayleigh-Benard convection and provides conclusions through numerical simulations and analysis. The study found that radiation delays the onset of convection at low Rayleigh numbers, but once convection is established, radiation increases convective flux and kinetic energy. Furthermore, radiative transfer contributes specifically to the potential energy balance and the thermal energy balance, weakening at high Rayleigh numbers. The paper also analyzes the effects of radiative transfer on turbulence budgets of mechanical and thermal fluctuations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Omar Rahli, Najwa Mimouni, Rachid Bennacer
Summary: The study investigates the natural convection heat transfer characteristics in a corrugated surface enclosure filled with fluid under Rayleigh-Bénard (RB) instability. It aims to analyze the combined physical and geometric effects on convective flow behavior for improving the engineering Polymerase Chain Reaction (PCR) process. The numerical investigation uses grid generation and finite volume approach with quadratic scheme approximation to discretize governing differential equations.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Justine Noel, Christel Metivier, Simon Becker, Sebastien Leclerc
Summary: Natural convection in melting material was experimentally studied using Magnetic Resonance Imaging. The experiments revealed enhanced transient evolution of liquid height under convection, as well as a 4-fold increase in steady averaged liquid height in the convective regime. The convection patterns observed were in the form of hexagons/polygons, with scaling laws converging to beta = 1/4 showing an increase in convective intensity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Inderpreet Singh, Satbir Singh Sehgal, Vikrant Khullar
Summary: Radiation-driven transport mechanisms in nanofluid filled enclosures have been investigated in this study. The effects of various parameters on temperature and flow fields were analyzed. The results show that steady state can be achieved unconditionally under adiabatic boundary conditions, while the onset and transition of natural convection are significantly influenced by the mode of absorption and the enclosure inclination angle under isothermal boundaries.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Mechanics
Shashwat Bhattacharya, Mahendra K. Verma, Ravi Samtaney
Summary: In this paper, the GL model is extended for predicting Reynolds number and Nusselt number in turbulent Rayleigh-Benard convection. Functional forms for dissipation rates prefactors are used, and machine learning is applied to determine revised predictions that show better agreement with past results in a three-dimensional unit box setting.
Article
Physics, Fluids & Plasmas
Shenglei Qin, Guoxiang Hou, Liuming Yang, Xu Liu, Haoze Luo
Summary: This paper introduces a simplified lattice Boltzmann method that solves macroscopic equations in a single step. It can accurately simulate thermal flow problems and has good numerical stability.
Article
Mechanics
Alexander Blass, Roberto Verzicco, Detlef Lohse, Richard J. A. M. Stevens, Dominik Krug
Summary: In this study, large-scale circulation of turbulent Rayleigh-Benard convection was investigated in a large container with high Rayleigh number conditions. The results showed that the properties of LSC remain consistent even with varying boundaries, and the transition to the ultimate regime is predicted to occur in unconstrained geometries. Additionally, observations were in line with experimental data from Gottingen.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Mechanical
Oussama Abahri, Djamel Sadaoui, Kacem Mansouri, Abdelkader Mojtabi, Marie Catherine Mojtabi
MECHANICS & INDUSTRY
(2017)
Article
Thermodynamics
Abdelkader Mojtabi, Bafetigue Ouattara, D. Andrew S. Rees, Marie-Catherine Charrier-Mojtabi
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2018)
Article
Mechanics
Marie Catherine Charrier-Mojtabi, Bilal Elhajjar, Bafetigue Ouattara, Abdelkader Mojtabi, Pierre Costeseque
COMPTES RENDUS MECANIQUE
(2011)
Article
Mechanics
B. Ouattara, A. Khouzam, A. Mojtabi, M. C. Charrier-Mojtabi
FLUID DYNAMICS RESEARCH
(2012)
Article
Thermodynamics
Bilal Elhajjar, Abdelkader Mojtabi, Pierre Costeseque, Marie-Catherine Charrier-Mojtabi
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2010)
Article
Thermodynamics
Marie Catherine Charrier-Mojtabi, Alain Fontaine, Abdelkader Mojtabi
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2012)
Article
Thermodynamics
Ali Khouzam, Abdelkader Mojtabi, Marie-Catherine Charrier-Mojtabi, Bafetigue Ouattara
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2013)
Article
Engineering, Chemical
Y. P. Razi, A. Mojtabi, M. C. Charrier-Mojtabi
TRANSPORT IN POROUS MEDIA
(2009)
Article
Chemistry, Physical
M. C. Charrier-Mojtabi, X. Jacob, T. Dochy, A. Mojtabi
EUROPEAN PHYSICAL JOURNAL E
(2019)
Article
Thermodynamics
Abdelkader Mojtabi, Ali Khouzam, Loujaine Yacine, Marie-Catherine Charrier-Mojtabi
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2019)
Article
Mechanics
M. C. Charrier-Mojtabi, B. Elhajjar, A. Mojtabi
Article
Thermodynamics
MCC Mojtabi, YP Razi, K Maliwan, A Mojtabi
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2004)
Article
Thermodynamics
O Sovran, G Bardan, A Mojatbi, MC Charrier-Mojtabi
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2000)
