Two-dimensional model of trapezoidal solar pond based on large eddy simulation

The performance of some commonly used eddy-viscosity turbulence models has been evaluated using direct numerical simulation (DNS) and large-eddy simulation (LES) data. Two configurations have been tested, a two-dimensional boundary layer undergoing pressure-driven separation, and a square duct. The DNS and LES were used to assess the k−ε, ζ−f, k−ω, and Spalart–Allmaras models. For the two-dimensional separated boundary layer, anisotropic effects are not significant and the eddy-viscosity assumption works well. However, the near-wall treatment used in k−ε models was found to have a critical effect on the predictive accuracy of the model (and, in particular, of separation and reattachment points). None of the wall treatments tested resulted in accurate prediction of the flow field. Better results were obtained with models that do not require special treatment in the inner layer (ζ−f, k−ω, and Spalart–Allmaras models). For the square duct calculation, only a nonlinear constitutive relation was found to be able to capture the secondary flow, giving results in agreement with the data. Linear models had significant error.

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Large-Eddy Simulation of Erosion and Deposition over Multiple Two-Dimensional Gaussian Hills in a Turbulent Boundary Layer

Boundary-Layer Meteorology ◽

10.1007/s10546-019-00463-2 ◽

2019 ◽

Vol 173 (2) ◽

pp. 193-222 ◽

Cited By ~ 1

Author(s):

G. Huang ◽

C. Le Ribault ◽

I. Vinkovic ◽

S. Simoëns

Keyword(s):

Boundary Layer ◽

Turbulent Boundary Layer ◽

Large Eddy Simulation ◽

Two Dimensional ◽

Erosion And Deposition ◽

Eddy Simulation ◽

Large Eddy

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Effect of Pulsation and Acceleration of Liquid Metal Turbulent Flow Through a Horizontal Channel by Large Eddy Simulation

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4046259 ◽

2020 ◽

Vol 6 (4) ◽

Author(s):

N. Satish ◽

K. Venkatasubbaiah

Keyword(s):

Heat Transfer ◽

Liquid Metal ◽

Large Eddy Simulation ◽

Turbulent Flow ◽

Horizontal Channel ◽

Two Dimensional ◽

Unsteady State ◽

Eddy Simulation ◽

Large Eddy ◽

Flow Through

Abstract Pulsation and acceleration of liquid metal turbulent flow through a horizontal channel has been numerically studied using a large eddy simulation (LES) technique. The effect of inlet pulsation and acceleration on flow and heat transfer characteristics of low Prandtl number liquid metal flow have been investigated and reported here. Results have been presented for different Reynolds numbers, different amplitudes, and frequency with constant bottom wall thickness. The flow field is modeled as unsteady-state two-dimensional incompressible turbulent-forced convection flow. Turbulence is modeled using a LES technique. Two-dimensional unsteady-state heat conduction equation is solved to know the temperature distribution in the solid region. Finite difference method solver is developed for solving the governing equations using sixth-order accuracy of compact schemes. The average Nusselt number shows cyclic variation with respect to time in pulsation flows. The enhancement of heat transfer with pulsation at amplitude 0.4 and frequency 100 Hz is 6.51%. The rate of heat transfer increases in pulsation flow compared to quasi-steady flow. The inlet acceleration shows a significant effect on flow characteristics. The present results are compared with direct numerical simulation (DNS) results available in the literature and matching well with DNS data.

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