Direct numerical simulation of a differentially heated cavity of aspect ratio 4 with Rayleigh numbers up to – Part II: Heat transfer and flow dynamics

Trias, F. X.; Gorobets, A.; Sòria, M.; Oliva, A.

doi:10.1016/j.ijheatmasstransfer.2009.10.027

Cited by 67 publications

(43 citation statements)

References 15 publications

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“…(11); these values were calculated to be 0.082 and 0.325, respectively. Therefore, the correlation for the airproof cavity investigated in this study can be given as, Nu ¼ 0:082 Á Ra 0:325 ð12Þ…”

Section: Resultsmentioning

confidence: 99%

“…That is, there is no air movement from the exterior environment to the cavity or from the cavity to the outside, and there is a temperature difference between the interior and exterior surfaces. This phenomenon of differentially heated/cooled cavities has been studied extensively in the literature [2][3][4][5][6][7][8][9][10][11][12][13]. On the other hand, some double skin facade applications have been designed considering open cavity natural convection [14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

“…The above studies related to an enclosed cavity for an airproof double skin facade mainly have low Rayleigh numbers. However, Rayleigh numbers are larger than 10 10 in some studies [10][11][12][13]. Trias et al [10,11] studied different Rayleigh numbers from 6.4 ⁄ 10 8 to 10 11 .…”

Section: Introductionmentioning

confidence: 99%

“…However, Rayleigh numbers are larger than 10 10 in some studies [10][11][12][13]. Trias et al [10,11] studied different Rayleigh numbers from 6.4 ⁄ 10 8 to 10 11 . Saury et al [12] analyzed natural convection in an air cavity with experimental results at large Rayleigh numbers of up to 1.2 ⁄ 10 11 .…”

Section: Introductionmentioning

confidence: 99%

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Experimental and numerical investigation of natural convection in a double skin facade

İnan

Başaran

Ezan

2016

Applied Thermal Engineering

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In this study, airflow and heat transfer in a rectangular cavity that simulates a double skin facade and includes natural convection were examined numerically and experimentally. This cavity separates the exterior space and the thermally controlled interior space. The temperatures of the surfaces that interact with these spaces were determined experimentally, while the other surfaces were regarded as adiabatic. With these temperature values, the parameters of the numerical study were defined. After the validation of the numerical model was completed based on experimental studies in the literature, the results related to flow and heat transfer in the cavity were analyzed. The numerical model provided results that agree with the air temperature values found experimentally in the cavity. Accordingly, in natural convection, with Rayleigh numbers ranging from 8.59 ∗ 109 to 1.41 ∗ 1010 and the effect of buoyancy on the regions close to the surface, the increasing tendency of the average Nusselt number from 142.6 to 168.8 was shown. In addition, a correlation between the Rayleigh and Nusselt numbers for a cavity aspect ratio of 8.64 was constructed to evaluate the heat flux; this correlation was also shown graphically.Scientific and Technological Research Council of Turkey (112M170

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental and numerical investigation of natural convection in a double skin facade

İnan

Başaran

Ezan

2016

Applied Thermal Engineering

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“…Since now the performance of the C 4 approximation has been successfully tested for a turbulent channel flow [3] and an air-filled (Pr = 0.71) differentially heated cavity (DHC) of height aspect ratio A = 4 at Ra-numbers (based on the cavity height) 10 10 [5, 6] and 10 11 [7] by means of direct comparison with the DNS results [8,9,10]. In the latter cases, the filter width ε was treated as a parameter.…”

Section: -Regularization Modellingmentioning

confidence: 99%

Parameter-Free Symmetry-Preserving Regularization Modelling of Turbulent Natural Convection Flows

Trias

Verstappen

Sòria

et al. 2010

Notes on Numerical Fluid Mechanics and Multidisciplinary Design

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Since direct numerical simulations of natural convection flows cannot be performed at high Ra-numbers, a dynamically less complex mathematical formulation is sought. In the quest for such a formulation, we consider regularizations (smooth approximations) of the nonlinearity. The regularization method basically alters the convective terms to reduce the production of small scales of motion by means of vortex stretching. In doing so, we propose to preserve the symmetry and conservation properties of the convective terms exactly. This requirement yields a novel class of regularizations that restrain the convective production of smaller and smaller scales of motion by means of vortex stretching in an unconditional stable manner, meaning that the velocity cannot blow up in the energy-norm (in 2D also: enstrophy-norm). The numerical algorithm used to solve the governing equations preserves the symmetry and conservation properties too. The regularization model is successfully tested for a 3D natural convection flow in air-filled (Pr = 0.71) differentially heated cavity of height aspect ratio 4 at Ra = 10 10 and 10 11 . Moreover, a method to dynamically determine the regularization parameter (local filter length) is also proposed and tested.

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Regularization modeling of buoyancy-driven flows

et al. 2011

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Simulation of turbulent flow by means of direct numerical simulation (DNS) and large-eddy simulation (LES) started almost fifty years ago. Probably the earliest paper on the application of LES was by Smagorinksy in the March 1963 issue of Monthly Weather Review. Although Smagorinsky did not mention the term largeeddy simulation explicitly, he proposed a model to represent the effects of smallscale eddies on the large-scale dynamics of the flow, which was treated explicitly. Smagorinsky applied his now famous model to the simulation and study of the dynamics of the general circulation in the earth's atmosphere. Direct numerical simulation of wall-bounded flows started some twenty years later with the well-known 1987 paper in the Journal of Fluid Mechanics by Kim, Moin and Moser on DNS of turbulent channel flow at a bulk Reynolds number of 3300. Although DNS had been applied before on homogeneous, isotropic turbulence and some preliminary studies on under-resolved channel flow had been performed, this paper presented the first fully resolved DNS of a wall-bounded turbulent flow. The large number of citations reported on Web of Science proves the tremendous impact both papers had and still have on research in turbulence. The continuing growth of computational power has increasingly stimulated the usage of DNS and LES, since LES and in some applications even DNS can now be used as a design tool for several practical and industrial problems. This is reflected by the possibility of CFD software packages to perform LES, although this should still be treated with care. On the other hand, for flow in simple geometries, such as channel flow, DNS has been extended to higher and higher Reynolds numbers, which brings the study of fundamental properties of turbulent flow at large Reynolds numbers within reach. These examples highlight the two major reasons for usage of DNS and LES: application-driven research and fundamental research into the nature of turbulence and into turbulence models. The history of this research over the past two decades can well be grasped from the contents of the ERCOFTAC series of Workshops on Direct and Large-Eddy Simulation.

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Direct numerical simulation of a differentially heated cavity of aspect ratio 4 with Rayleigh numbers up to – Part II: Heat transfer and flow dynamics

Cited by 67 publications

References 15 publications

Experimental and numerical investigation of natural convection in a double skin facade

Experimental and numerical investigation of natural convection in a double skin facade

Parameter-Free Symmetry-Preserving Regularization Modelling of Turbulent Natural Convection Flows

Regularization modeling of buoyancy-driven flows

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