Lagrangian dynamic large-eddy simulation of wind turbine near wakes combined with an actuator line method

Wind turbine wakes have significant effects on the production efficiency and fatigue loads, and these effects should be considered in the optimization of wind turbine structure and wind farm layouts. In this paper, a numerical model combining Lagrangian dynamic large-eddy models and actuator line methods (ALMs) is implemented to investigate the wind turbine near wakes at three representative tip speed ratios (TSRs). In the model, several model parameters that have been justified based on the existing literature and experiments are utilized to enhance the numerical stability and accuracy. These parameters are related to a physically meaningful length scale in the Gaussian smoothing function, a Prandtl tip/hub-loss factor and a 3D correction for airfoil data. The model is compared to the MEXICO measurements, in which a detailed stereo PIV measurement is carried out. According to the comparison of rotor power coefficients between the prediction and the measurements, there is a slight overestimate at TSRs of 6.67 and 10, while a slight underestimate at TSR of 4.17. Additionally, according to the comparison of streamwise traverses and spanwise distribution of axial velocities, good agreement is achieved at both TSRs of 4.17 and 6.67, while visible difference is found at TSR of 10. Moreover, the simulation result shows a helical behavior of wake tip vortices induced by the turbine rotor. This behavior gets more pronounced with a decreasing TSR. The tip vortices also give a reasonable explanation of why the maximum velocity deficit and turbulence intensity occur near the blade tip of wind turbines.

[1]  R. Cucitore,et al.  On the effectiveness and limitations of local criteria for the identification of a vortex , 1999 .

[2]  P. Wesseling,et al.  Geometric multigrid with applications to computational fluid dynamics , 2001 .

[3]  D. Lilly,et al.  A proposed modification of the Germano subgrid‐scale closure method , 1992 .

[4]  Krishnan Mahesh,et al.  A Lagrangian subgrid-scale model with dynamic estimation of Lagrangian time scale for large eddy simulation of complex flows , 2012 .

[5]  J. G. Schepers,et al.  Engineering models in wind energy aerodynamics : Development, implementation and analysis using dedicated aerodynamic measurements , 2012 .

[6]  Francesco Castellani,et al.  An application of the actuator disc model for wind turbine wakes calculations , 2013 .

[7]  Curran Crawford,et al.  Mesh and load distribution requirements for actuator line CFD simulations , 2012 .

[8]  Young-Ho Lee,et al.  Large eddy simulation of the wind turbine wake characteristics in the numerical wind tunnel model , 2013 .

[9]  Daniel Micallef,et al.  Analysis of Mexico wind tunnel measurements: Final report of IEA Task 29, Mexnext (Phase 1) , 2012 .

[10]  Martin Raubal,et al.  Assessment of the wake effect on the energy production of onshore wind farms using GIS , 2014 .

[11]  Fernando Porté-Agel,et al.  Large-eddy simulation of atmospheric boundary layer flow through wind turbines and wind farms , 2011 .

[12]  Jens Nørkær Sørensen,et al.  Numerical Modeling of Wind Turbine Wakes , 2002 .

[13]  J. Sørensen,et al.  Wind turbine wake aerodynamics , 2003 .

[14]  Gavin Tabor,et al.  Inlet conditions for large eddy simulation: A review , 2010 .

[15]  B. Koren,et al.  Review of computational fluid dynamics for wind turbine wake aerodynamics , 2011 .

[16]  Elias Balaras,et al.  Scale-Similar Models for Large-Eddy Simulations , 1999 .

[17]  Aie,et al.  World Energy Outlook 2013 , 2013 .

[18]  P. Moin,et al.  A dynamic subgrid‐scale eddy viscosity model , 1990 .

[19]  Stefan Ivanell,et al.  Validation of the actuator line method using near wake measurements of the MEXICO rotor , 2015 .

[20]  R. Mikkelsen.  Actuator Disc Methods Applied to Wind Turbines , 2004 .

[21]  Y. Dubief,et al.  On coherent-vortex identification in turbulence , 2000 .

[22]  Jens Nørkær Sørensen,et al.  Actuator line/Navier–Stokes computations for the MEXICO rotor: comparison with detailed measurements , 2012 .

[23]  Aie.  World Energy Outlook 2011 , 2001 .

[24]  Patrick Moriarty,et al.  AeroDyn Theory Manual , 2005 .

[25]  J. Sørensen,et al.  Analysis of wake states by a full‐field actuator disc model , 1998 .

[26]  F. Porté-Agel,et al.  A Wind-Tunnel Investigation of Wind-Turbine Wakes: Boundary-Layer Turbulence Effects , 2009 .

[27]  U. Piomelli.  Wall-layer models for large-eddy simulations , 2008 .

[28]  Karoly Nagy,et al.  Use of renewable energy sources in light of the “New Energy Strategy for Europe 2011–2020” , 2012 .

[29]  U. Piomelli,et al.  Turbulent structures in accelerating boundary layers , 2000 .

[30]  W. Rodi.  DNS and LES of some engineering flows , 2006 .

[31]  S. Frandsen.  Turbulence and turbulence-generated structural loading in wind turbine clusters , 2007 .

[32]  C. Meneveau,et al.  A Lagrangian dynamic subgrid-scale model of turbulence , 1994, Journal of Fluid Mechanics.

[33]  James Demmel,et al.  Applied Numerical Linear Algebra , 1997 .

[34]  Eduard Muljadi,et al.  Pitch-controlled variable-speed wind turbine generation , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[35]  Dennis Y.C. Leung,et al.  Wind energy development and its environmental impact: A review , 2012 .

[36]  Julio Hernández,et al.  Survey of modelling methods for wind turbine wakes and wind farms , 1999 .

[37]  Leonard Roberts,et al.  Navier-Stokes computation of wing/rotor interaction for a tilt rotor in hover , 1991 .

[38]  Egon Hassel,et al.  Synthesis of homogeneous anisotropic turbulent fields with prescribed second‐order statistics by the random spots method , 2007 .

[39]  J G Schepers,et al.  The MEXICO project (Model Experiments in Controlled Conditions): The database and first results of data processing and interpretation , 2007 .

[40]  Daniel Micallef,et al.  Final report of IEA Task 29, Mexnext (Phase 1): Analysis of Mexico wind tunnel measurements , 2012 .

[41]  Jens Nørkær Sørensen,et al.  Numerical simulations of wake characteristics of a wind turbine in uniform inflow , 2010 .

[42]  C. Meneveau,et al.  Scale-Invariance and Turbulence Models for Large-Eddy Simulation , 2000 .

[43]  Jens Nørkær Sørensen,et al.  Actuator surface model for wind turbine flow computations , 2007 .

[44]  Miguel Esteban,et al.  Current developments and future prospects of offshore wind and ocean energy , 2012 .