Large eddy simulations of the flow past wind turbines: actuator line and disk modeling

Wind Energy ◽  
2014 ◽  
Vol 18 (6) ◽  
pp. 1047-1060 ◽  
Author(s):  
Luis A. Martínez-Tossas ◽  
Matthew J. Churchfield ◽  
Stefano Leonardi
Keyword(s):  
Wind Turbines ◽  
Large Eddy Simulations ◽  
Flow Past ◽  
Large Eddy

Large Eddy Simulations of Curled Wakes from Tilted Wind Turbines

2021 ◽  
Author(s):  
Hannah M. Johlas ◽  
David P. Schmidt ◽  
Matthew A. Lackner
Keyword(s):  
Wind Turbines ◽  
Large Eddy Simulations ◽  
Large Eddy

Large-eddy simulation of turbulent flow past wind turbines/farms: the Virtual Wind Simulator (VWiS)

Wind Energy ◽  
2014 ◽  
Vol 18 (12) ◽  
pp. 2025-2045 ◽  
Author(s):  
Xiaolei Yang ◽  
Fotis Sotiropoulos ◽  
Robert J. Conzemius ◽  
John N. Wachtler ◽  
Mike B. Strong
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Wind Turbines ◽  
Eddy Simulation ◽  
Flow Past ◽  
Large Eddy

Large Eddy Simulations of Flow Past Two Pipelines in Tandem in Close Proximity to the Seabed

2017 ◽  
Author(s):  
Zhong Li ◽  
Mia Abrahamsen Prsic ◽  
Muk Chen Ong ◽  
Boo Cheong Khoo
Keyword(s):  
Drag Coefficient ◽  
Recirculation Zone ◽  
Separation Distance ◽  
Large Eddy Simulations ◽  
Plane Wall ◽  
Scale Model ◽  
Tandem Cylinders ◽  
Flow Past ◽  
Large Eddy ◽  
The Mean

Three-dimensional Large Eddy Simulations (LES) with Smagorinsky subgrid scale model have been performed for the flow past two free-spanning marine pipelines in tandem placed in the vicinity of a plane wall at a very small gap ratio, namely G/D = 0.1, 0.3 and 0.5. The ratio of cylinder center-to-center distance to cylinder diameter, or pitch ratio, L/D, considered in the simulations is taken as L/D = 2 and 5. This work serves as an extension of Abrahamsen Prsic et al. (2015) [1]. In essence, six sets of simulations have been performed in the subcritical Reynolds number regime at Re = 1.31 × 104. Our major findings can be summarized as follows. (1) At both pitch ratios, the wall proximity has a decreasing effect on the mean drag coefficient of the upstream cylinder. At L/D = 2, the mean drag coefficient of the downstream cylinder is negative since it is located within the drag inversion separation distance. (2) At L/D = 2, a squarish cavity-like flow exists between the tandem cylinders and flow circulates within the cavity. A long lee-wake recirculation zone is found behind the downstream cylinder at G/D = 0.1. However, a much smaller lee-wake recirculation zone is noticed at L/D = 5 with G/D = 0.1. (3) At L/D = 2, the reattachment is biased to the bottom shear layer due towards the deflection from the plane wall, which leads to the formation of the slanted squarish cavity-like flow where the flow circulates between the tandem cylinders.

A Parametric Study of Turbulent Flow Past a Circular Cylinder Using Large Eddy Simulation

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
W. Sidebottom ◽  
A. Ooi ◽  
D. Jones
Keyword(s):  
Reynolds Number ◽  
Finite Difference ◽  
Circular Cylinder ◽  
Stokes Equations ◽  
Finite Difference Methods ◽  
Large Eddy Simulations ◽  
Near Wake ◽  
Flow Past ◽  
Large Eddy ◽  
Difference Methods

Flow over a circular cylinder at a Reynolds number of 3900 is investigated using large eddy simulations (LES) to assess the affect of four numerical parameters on the resulting flow-field. These parameters are subgrid scale (SGS) turbulence models, wall models, discretization of the advective terms in the governing equations, and grid resolution. A finite volume method is employed to solve the incompressible Navier–Stokes equations (NSE) on a structured grid. Results are compared to the experiments of Ong and Wallace (1996, “The Velocity Field of the Turbulent Very Near Wake of a Circular Cylinder,” Exp. Fluids, 20(6), pp. 441–453) and Lourenco and Shih (1993, “Characteristics of the Plane Turbulent Near Wake of a Circular Cylinder: A Particle Image Velocimetry Study,” private communication (taken from Ref. [2]); and the numerical results of Beaudan and Moin (1994, “Numerical Experiments on the Flow Past a Circular Cylinder at Sub-Critical Reynolds Number,” Technical Report No. TF-62), Kravchenko and Moin (2000, “Numerical Studies of Flow Over a Circular Cylinder at ReD = 3900,” Phys. Fluids, 12(2), pp. 403–417), and Breuer (1998, “Numerical and Modelling Influences on Large Eddy Simulations for the Flow Past a Circular Cylinder,” Int. J. Heat Fluid Flow, 19(5), pp. 512–521). It is concluded that the effect of the SGS models is not significant; results with and without a wall model are inconsistent; nondissipative discretization schemes, such as central finite difference methods, are preferred over dissipative methods, such as upwind finite difference methods; and it is necessary to properly resolve the boundary layer in the vicinity of the cylinder in order to accurately model the complex flow phenomena in the cylinder wake. These conclusions are based on the analysis of bulk flow parameters and the distribution of mean and fluctuating quantities throughout the domain. In general, results show good agreement with the experimental and numerical data used for comparison.

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