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The basic stationary buoyant flow in a vertical annular porous passage induced by a boundary temperature difference is investigated. The vertical cylindrical boundaries are considered both isothermal and permeable to external fluid…

Fluid Dynamics · Physics 2023-02-03 A. Barletta , M. Celli , D. A. S. Rees

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

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…

Fluid Dynamics · Physics 2021-07-26 Xiaowei Xu , Andrew S. H. Ooi , Richard D. Sandberg

The shape of velocity and temperature profiles near the horizontal conducting plates in turbulent Rayleigh-B\'{e}nard convection are studied numerically and experimentally over the Rayleigh number range $10^8\lesssim…

We report measurements of properties of turbulent thermal convection of a fluid with a Prandtl number $\Pra=4.38$ in a cylindrical cell with an aspect ratio $\Gamma=0.50$. The rotational symmetry was broken by a small tilt of the sample…

Fluid Dynamics · Physics 2015-06-05 Stephan Weiss , Guenter Ahlers

The divergence-free time-independent velocity vector field has been determined so as to maximise heat transfer between two parallel plates of a constant temperature difference under the constraint of fixed total enstrophy. The present…

Fluid Dynamics · Physics 2018-08-03 Shingo Motoki , Genta Kawahara , Masaki Shimizu

We investigate the influence of the thermal properties of the boundaries in turbulent Rayleigh-B\'enard convection on analytical upper bounds on convective heat transport. We model imperfectly conducting bounding plates in two ways: using…

Fluid Dynamics · Physics 2010-08-17 Ralf W. Wittenberg

Direct numerical simulations of turbulent heat transfer in fully-developed channel flows have been performed in a range of friction Reynolds number between 60 and 180, based on the friction velocity and the channel half width $\delta$, with…

Fluid Dynamics · Physics 2014-09-18 Takahiro Tsukahara , Kaoru Iwamoto , Hiroshi Kawamura , Tetsuaki Takeda

A pure and incompressible material is confined between two plates such that it is heated from below and cooled from above. When its melting temperature is comprised between these two imposed temperatures, an interface separating liquid and…

Fluid Dynamics · Physics 2020-02-11 Jhaswantsing Purseed , Benjamin Favier , Laurent Duchemin , Eric W. Hester

Turbulent motions enhance the diffusion of large-scale flows and temperature gradients. Such diffusion is often parameterized by coefficients of turbulent viscosity ($\nu_{\rm t}$) and turbulent thermal diffusivity ($\chi_{\rm t}$) that are…

Fluid Dynamics · Physics 2022-12-07 Petri J. Käpylä , Nishant K. Singh

We investigate the structures of the near-plate velocity and temperature profiles at different horizontal positions along the conducting bottom (and top) plate of a Rayleigh-B\'{e}nard convection cell, using two-dimensional (2D) numerical…

This work investigates heat transport in rotating internally heated convection, for a horizontally periodic fluid between parallel plates under no-slip and isothermal boundary conditions. The main results are the proof of bounds on the mean…

Fluid Dynamics · Physics 2024-12-25 Ali Arslan

We present a numerical study of vorticity production and transport in the two-dimensional Rayleigh-B\'enard (RB) convection. Direct numerical simulations are carried out in the Rayleigh number ($Ra$) range $10^{5}\le Ra \le 10^{6}$, the…

Fluid Dynamics · Physics 2022-01-20 Ao Xu , Ben-Rui Xu , Li-Sheng Jiang , Heng-Dong Xi

Doubly diffusive convection is considered in a vertical slot where horizontal temperature and solutal variations provide competing effects to the fluid density while allowing the existence of a conduction state. In this configuration, the…

Fluid Dynamics · Physics 2023-01-24 C. Beaume , A. M. Rucklidge , J. Tumelty

Particle image velocimetry is applied to the lid-driven flow in a cube to validate the numerical prediction of steady - oscillatory transition at lower than ever observed Reynolds number. Experimental results agree with the numerical…

Fluid Dynamics · Physics 2015-05-28 A. Liberzon , Y. Feldman , A. Yu. Gelfgat

The heat transport in rotating Rayleigh-B\'enard convection is considered in the limit of rapid rotation (small Ekman number $E$) and strong thermal forcing (large Rayleigh number $Ra$). The analysis proceeds from a set of asymptotically…

Fluid Dynamics · Physics 2015-06-19 Ian Grooms , Jared P Whitehead

This study explores heat and turbulent modulation in three-dimensional multiphase Rayleigh-B\'enard convection using direct numerical simulations. Two immiscible fluids with identical reference density undergo systematic variations in…

Fluid Dynamics · Physics 2024-08-26 Abbas Moradi Bilondi , Nicolò Scapin , Luca Brandt , Parisa Mirbod

Buoyancy effect on low-flow condition convective heat transfer of non-conventional coolants, such as liquid metal and molten salts, is a crucial safety factor to advanced reactors under transient or accidental scenarios. The distinct heat…

Fluid Dynamics · Physics 2022-04-04 Cheng-Kai Tai , Tri Nguyen , Arsen S. Iskhakov , Elia Merzari , Nam Dinh , Igor A. Bolotnov

A semi-explicit formula of solution to the boundary layer system for thermal layer derived from the compressible Navier-Stokes equations with the non-slip boundary condition when the viscosity coefficients vanish is given, in particular in…

Analysis of PDEs · Mathematics 2016-08-10 Cheng-Jie Liu , Ya-Guang Wang , Tong Yang

We carry out direct numerical simulation (DNS) of flow in a turbulent square duct by focusing on heat transfer effects, considering the case of unit Prandtl number. Reynolds numbers up to $Re_\tau \approx 2000$ are considered which are much…

Fluid Dynamics · Physics 2022-05-11 Davide Modesti , Sergio Pirozzoli