A review on natural convection in enclosures for engineering applications. The particular case of the parallelogrammic diode cavity

This paper aims to simulate the interaction between thermal surface radiation and nanofluid free convection in a two dimensional shallow cavity by lattice Boltzmann method. The supposed nanofluid is generated by a homogeneous mixture of water and nanoparticles of Al2O3. The upper and lower walls of cavity are maintained at cold and hot temperature, respectively; while the side walls are kept thermally insulated. The cavity aspect ratio is chosen as 5 which indicates a shallow one. The cavity all inner surfaces are considered as the gray diffuse emitters and reflectors of radiation. The computations are performed for the wide range of parameters as Ra = 104 and Ra = 105; e = 0 . 5 and e = 0 . 9 while nanoparticles volume fraction changes between 0.0 ≤ φ ≤ 0.04 at each case. As a result, the effects of emissivity and Rayleigh number are studied on the total heat transfer of radiation and free convection of nanofluid. The suitable validations are examined beside the useful grid study procedure. The results are presented as the profiles of velocity and temperature and also the streamlines and isotherms. Moreover the local and averaged Nusselt numbers are provided for the coupled and uncoupled states of radiation and free convection heat transfer mechanisms. It is seen that Nu m of total free convection and radiation would be more at higher Ra and e ; which indicates that radiation heat transfer coupled with free convection might affect the flow field and improve the Nusselt number.

The investigation of thermal radiation and free convection heat transfer mechanisms of nanofluid inside a shallow cavity by lattice Boltzmann method

Numerical simulation of air flow and heat transfer in domestic refrigerators

Conjugate natural convection combined with surface thermal radiation in a three-dimensional enclosure with a heat source

Étude numérique du couplage de la convection naturelle avec le rayonnement de surfaces en cavité carrée remplie d'air

Three-dimensional numerical simulation of convection and radiation in a differentially heated cavity using the discrete ordinates method

The coupling between non-gray radiation heat transfer and convection–conduction heat transfer is studied. The spectral line weighted sum of gray gases model ( slw ) is used to account for non-gray radiation properties. The aim of this work is to analyze the influence of the different approaches used when calculating the parameters of the slw model. Such strategies include the use of optimized model coefficients to reduce the number of operations, and the interpolation of the distribution function instead of the use of mathematical correlations. Non-gray calculations are also compared to gray solutions using the Planck mean absorption coefficient, which can be also calculated with the slw model. The radiative transfer equation ( rte ) is solved by means of the discrete ordinates method ( dom ). A natural convection driven cavity is chosen to couple radiation and conduction–convection energy transfer. Several cases, with a significant variation of the ratio between radiation to convection heat transfer, as well as the ratio between radiation to conduction heat transfer, are discussed.

Coupled radiation and natural convection: Different approaches of the slw model for a non-gray gas mixture

In the present work, turbulent natural convection in a tall differentially heated cavity of aspect ratio 5:1, filled with air (Pr = 0.7) under a Rayleigh number based on the height of 4.5 · 1010, is studied numerically. Two different situations have been analysed. In the first one, the cavity is filled with a transparent medium. In the second one, the cavity contains a grey participating gas. The turbulent flow is described by means of Large Eddy Simulation (LES) using symmetry-preserving discretizations. Simulations are compared with experimental data available in the literature and with Direct Numerical Simulations (DNS). Surface and gas radiation have been simulated using the Discrete Ordinates Method (DOM). The influence of radiation on fluid flow behaviour has also been analysed.

http://iopscience.iop.org/article/10.1088/1742-6596/318/4/042048/pdf

Turbulent natural convection in a differentially heated cavity of aspect ratio 5 filled with non-participating and participating grey media

Turbulent natural convection in a tall differentially heated cavity of aspect ratio 5:1, filled with air under a Rayleigh number based on the height of 4.51010 is studied numerically. Three different situations have been analysed. In the first one, the cavity is filled with a transparent medium. In the second one, the cavity is filled with a semigrey participating mixture of air and water vapour. In the last one the cavity contains a grey participating gas. The turbulent flow is described by means of Large Eddy Simulation (LES) using symmetry-preserving discretizations. Simulations are compared with experimental data available in the literature and with Direct Numerical Simulations (DNS). Surface and gas radiation have been simulated using the Discrete Ordinates Method (DOM). The influence of radiation on fluid flow behaviour has been analysed.

http://iopscience.iop.org/article/10.1088/1742-6596/395/1/012155/pdf

Study of turbulent natural convection in a tall differentially heated cavity filled with either non-participating, participating grey and participating semigrey media

G. Colomer

Papers

Three-dimensional numerical simulation of convection and radiation in a differentially heated cavity using the discrete ordinates method

Coupled radiation and natural convection: Different approaches of the slw model for a non-gray gas mixture

Turbulent natural convection in a differentially heated cavity of aspect ratio 5 filled with non-participating and participating grey media

Study of turbulent natural convection in a tall differentially heated cavity filled with either non-participating, participating grey and participating semigrey media

Advanced CFD&HT Numerical Modeling of Solar Tower Receivers☆