Transition prediction for a two-dimensional reynolds-averaged navier-stokes method applied to wind turbine airfoils

Wind Energy ◽  
10.1002/we.47 ◽  
2001 ◽  
Vol 4 (2) ◽  
pp. 61-75 ◽  
Author(s):  
Robert R. Brodeur ◽  
C. P. van Dam
Keyword(s):  
Wind Turbine ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Transition Prediction ◽  
Reynolds Averaged Navier Stokes ◽  
Turbine Airfoils

Applications of a Coupled Methodology to the Wind Turbine Airfoils

2012 ◽  
Vol 516-517 ◽  
pp. 572-576
Author(s):  
Qing Yuan Chen ◽  
Feng Lin Guo ◽  
Jin Quan Xu
Keyword(s):  
Wind Turbine ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Far Field ◽  
Two Dimensional ◽  
Aerodynamic Coefficients ◽  
Free Vortex ◽  
Vortex Model ◽  
Wind Tunnel Data ◽  
Turbine Airfoils

In this study, a coupled methodology is proposed for the aerodynamic behavior of wind turbine airfoils. The idea is to combine a Navier-Stokes solver with a free vortex model. The zone for the calculation of CFD is confined to the surrounding of the airfoil, whilst the free vortex model accounts for the far field of the airfoil. The flow around the airfoil is assumed to be two-dimensional (2D) incompressible fully turbulent flow, which is modeled by two equation turbulence models. The computed aerodynamic coefficients are presented for two wind turbine airfoils and compared with wind tunnel data.

Fluid Structure Interaction Simulations of the NREL 5 MW Wind Turbine—Part I: Aerodynamics and Blockage Effect

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ehsan Borouji ◽  
Takafumi Nishino
Keyword(s):  
Fatigue Life ◽  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Life Assessment ◽  
Navier Stokes ◽  
Element Analysis ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Reynolds Averaged Navier Stokes ◽  
Blockage Effect

Fluid structure interaction (FSI) simulations of the NREL 5 MW wind turbine are performed using a combination of two separate computational codes: abaqus for the finite element analysis (FEA) of turbine structures and STAR-CCM+ for the unsteady Reynolds-averaged Navier–Stokes analysis of flow around the turbine. The main aim of this study is to demonstrate the feasibility of using two-way coupled FSI simulations to predict the oscillation of the tower, as well as the rotor blades, of a full-scale wind turbine. Although the magnitude of the oscillation of the tower is much smaller than that of the blades, this oscillation is crucial for the assessment of the fatigue life of the tower. In this first part of the paper, the aerodynamic characteristics of the turbine predicted by the two-way coupled FSI simulations are discussed in comparison with those predicted by Reynolds-averaged Navier–Stokes simulations of a rigid turbine. Also, two different computational domains with a cross-sectional size of 2D × 2D and 4D × 4D (where D is the rotor diameter) are employed to investigate the blockage effect. The fatigue life assessment of the turbine is planned to be reported in the second part of the paper in the near future.

scholarly journals Two-dimensional numerical simulations of vortex-induced vibrations for wind turbine towers

2019 ◽  
Author(s):  
Axelle Viré ◽  
Adriaan Derksen ◽  
Mikko Folkersma ◽  
Kumayl Sarwar
Keyword(s):  
Numerical Simulations ◽  
Wind Turbine ◽  
Stokes Equations ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Supercritical Regime ◽  
Vortex Induced Vibrations ◽  
Wind Turbine Towers ◽  
High Reynolds

Abstract. Vortex-induced vibrations (VIV) of wind turbine towers can be critical during the installation phase, when the rotor-nacelle assembly is not yet mounted on the tower. The present work uses numerical simulations to study VIV of a two-dimensional cylinder under conditions that are representative of wind turbine towers, both from a fluid-dynamics and structural-dynamics perspective. First, the numerical tools and fluid-structure interaction algorithm are verified by considering a cylinder vibrating freely in a laminar flow. In that case, both the motion amplitude and frequency are shown to agree well with previous results from the literature. Second, VIV is modelled in the turbulent supercritical regime using Unsteady Reynolds-Averaged Navier–Stokes equations. In this context, the turbulence model is first validated on flow past a stationary cylinder at high Reynolds number. Then, results from forced vibrations are validated against experimental results for a range of reduced frequencies and velocities. It is shown that the behaviour of the aerodynamic damping changes with the frequency ratio, and can therefore lead to either self-limiting or self-exciting VIV when the cylinder is left to freely vibrate. Finally, results are shown for a freely-vibrating cylinder under realistic flow and structural conditions. While a clear lock-in map is identified and shows good agreement with published numerical and experimental data, the work also highlights the unsteady nature of the aerodynamic forces and motion under certain operating conditions.

Numerical investigation of vortex-induced vibration of an elastically mounted circular cylinder with One-degree of freedom at high Reynolds number using different turbulent models

2018 ◽  
Vol 233 (2) ◽  
pp. 443-453 ◽  
Author(s):  
Niaz Bahadur Khan ◽  
Zainah Ibrahim
Keyword(s):  
Reynolds Number ◽  
Flow Direction ◽  
Cross Flow ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Flow Around Cylinder ◽  
Reynolds Averaged Navier Stokes ◽  
Turbulent Models

This study presents numerical investigation for flow around cylinder at Reynolds number = 104 using different turbulent models. Numerical simulations have been conducted for fixed cylinder case at Reynolds number = 104 and for cylinder free to oscillate in cross-flow direction, at Reynolds number O (104), mass–damping ratio = 0.011 and range of frequency ratio wt = 0.4–1.4 using two-dimensional Reynolds-averaged Navier–Stokes equations. In the literature, the study has been conducted using detached eddy simulation, large eddy simulation and direct numerical simulation which are comparatively expensive in terms of computational cost. This study utilizes the Reynolds-averaged Navier–Stokes shear stress transport k-ω and realizable k-ε models to investigate the flow around fixed cylinder and flow around cylinder constrained to oscillate in cross-flow direction only. Hydrodynamic coefficients, vortex mode shape and maximum amplitude ( Ay/ D) extracted from this study are compared with detached eddy simulation, large eddy simulation and direct numerical simulation results. Results obtained using two-dimensional Reynolds-averaged Navier–Stokes shear stress transport k-ω model are encouraging, while realizable k-ε model is unable to capture the entire response branches. In addition, broad range of “lock-in” region is observed due to delay in capturing the transition from upper to lower branch during two-dimensional realizable k-ε analyses.

The Actuator Surface Model: A New Navier–Stokes Based Model for Rotor Computations

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
Wen Zhong Shen ◽  
Jian Hui Zhang ◽  
Jens Nørkær Sørensen
Keyword(s):  
Wind Turbine ◽  
Numerical Technique ◽  
Angle Of Attack ◽  
Vertical Axis ◽  
Navier Stokes ◽  
Surface Model ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Flow Past ◽  
Surface Technique

This paper presents a new numerical technique for simulating two-dimensional wind turbine flow. The method, denoted as the 2D actuator surface technique, consists of a two-dimensional Navier–Stokes solver in which the pressure distribution is represented by body forces that are distributed along the chord of the airfoils. The distribution of body force is determined from a set of predefined functions that depend on angle of attack and airfoil shape. The predefined functions are curve fitted using pressure distributions obtained either from viscous-inviscid interactive codes or from full Navier–Stokes simulations. The actuator surface technique is evaluated by computing the two-dimensional flow past a NACA 0015 airfoil at a Reynolds number of 106 and an angle of attack of 10deg and by comparing the computed streamlines with the results from a traditional Reynolds-averaged Navier–Stokes computation. In the last part, the actuator surface technique is applied to compute the flow past a two-bladed vertical axis wind turbine equipped with NACA 0012 airfoils. Comparisons with experimental data show an encouraging performance of the method.

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