Effects of transition, turbulence and yaw on the performance of horizontal axis wind turbines

Xu, Guanpeng; Sankar, Lakshmi N.

doi:10.2514/6.2000-48

Cited by 32 publications

(18 citation statements)

References 4 publications

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“…The asymptotic value of + ω in the laminar sublayer is given by (4) where (5) and (6) where S k is the roughness height. In the logarithmic region, the value of + ω is (7) which leads to the value of ω in the wall cell as .…”

Section: K-ω Sst Turbulence Modelmentioning

confidence: 99%

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CFD Investigation on the aerodynamic characteristics of a small-sized wind turbine of NREL PHASE VI operating with a stall-regulated method

Lee

2012

J Mech Sci Technol

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The objective of this investigation is to clearly understand the aerodynamic characteristics of a small-sized wind turbine of NREL Phase VI, operating with a stall-regulated method using CFD code. Based on this, it is possible to provide turbine designers with the aerodynamic design data to increase efficiency and improve performance in the design phase of future small-sized wind turbine blades. Moreover, a comparison was made between experimental datasets, in order to verify the reliability and validity of the analysis results. The first height in the normal direction from the surface of a rotor blade is about 0.2 mm, and the average value of y + is about 7 at 7 m/s. The domain is chosen to consist of only two hexahedral mesh regions, namely the interior region, including the wind turbine blade, and the external region excluding the rectangle. The total cell number of the numerical grid is about N g = 3.0 × 10 6 . Five different inflow velocities, in the range V in = 7.0-25.1 m/s, are used for the rotor blade calculations. The calculated power coefficient is about 0.35 at a TSR of 5.41, corresponding to 7 m/s, and showed considerably good agreement with the experimental measurements, to within 0.08%. It was observed that the 3-D stall begins to generate near the blade root at a wind speed of 7 m/s. Therefore, root design approaches considering the appropriate selection of the angle of attack and the thickness are very important in order to generate the stall on the blade root. Through a clear understanding of aerodynamic characteristics of a small-sized NREL Phase VI wind turbine, it is expected that this useful aerodynamic data will be made available to designers as guidance in designing stall-regulated wind turbine blades in the development phase of small-sized wind turbine systems in the future.

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Section: K-ω Sst Turbulence Modelmentioning

confidence: 99%

“…Studies on full Navier-Stokes simulations of wind turbine rotors have been performed by Duque [2], Xu and Sankar [3,4], Sørensen and Hansen [5], and Sørensen and Michelsen [6]. Additionally, a large number of rotor simulations have been performed by the helicopter community.…”

Section: Introductionmentioning

confidence: 99%

CFD Investigation on the aerodynamic characteristics of a small-sized wind turbine of NREL PHASE VI operating with a stall-regulated method

Lee

2012

J Mech Sci Technol

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“…Despite the difficulties [14], various modeling approaches have been developed or improved to investigate the unsteady aerodynamics of two wind turbines in yaw [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The dynamic stall phenomenon has been studied using Beddoes-Leishman dynamic stall model validated against the experimental results [27].…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of the Aerodynamic Performance of the New MEXICO Rotor under Yaw Conditions

2018

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Abstract:The influence of yaw misalignment on the aerodynamic performance of the New MEXICO rotor is investigated using blade-resolved Computational Fluid Dynamics (CFD) approaches with three wind speeds considered at a fixed yaw angle of 30 degrees. The air-load predictions and near wake characteristics from the numerical results are compared and discussed against the most recent wind tunnel test data. The nacelle impact, dynamic stall phenomenon and wake characteristics are analyzed, demonstrating the yaw effects and numerical issues raised from Reynolds-Averaged Navier Stokes (RANS) and Detached Eddy Simulation (DES) computations.

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“…There are several models to analyse the skewed wake effects of the wind rotor [11]. According to the actuator disc theory [6], the skewed wake expansion is in direction of the downwind blade for yawed flow condition.…”

Section: Development Of a Model To Investigate The Yaw Behaviour Of Smentioning

confidence: 99%

Development of a model to investigate the yaw behaviour of small horizontal axis wind turbines

Narayana

Putrus

Leung

et al. 2011

Proceedings of the Institution of Mechanical Engineers, Part A:

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Almost all small wind turbines have a tail vane to point the wind rotor into the wind direction. Various types of control mechanisms are used to protect the wind turbines from highwind speeds. In this study, a generic model of a wind turbine is developed to investigate the yaw operation of small-scale horizontal axis wind turbines (HAWT) with a single tail vane. A tilt-up wind turbine is considered here as most of the other HAWT types can be simplified to a state of this model. In the tilted up wind turbines, the wind rotor is free to move around the horizontal axis as well as the vertical one. When the wind speed exceeds the rated value, the wind rotor tilts upwards, taking up a stable position with an inclination towards the direction of the wind, thus controlling the wind component responsible for power generation. This article describes the development of a mathematical model of small-scale HAWT using the D'Alembert's principle to investigate the complex behaviour of the wind turbine under transient and steady-state operating conditions. In this model, the blade element theory was adapted to predict the aerodynamic forces on the wind rotor at each rotor position. Combining the modified blade element with the momentum theories makes it possible to evaluate flow fields of induced velocities around the wind rotor. Yaw movements are modelled by considering dynamic responses of the tail vane. Finally, simulation results are presented to illustrate the yaw behaviour of a small wind turbine.

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Effects of transition, turbulence and yaw on the performance of horizontal axis wind turbines

Cited by 32 publications

References 4 publications

CFD Investigation on the aerodynamic characteristics of a small-sized wind turbine of NREL PHASE VI operating with a stall-regulated method

CFD Investigation on the aerodynamic characteristics of a small-sized wind turbine of NREL PHASE VI operating with a stall-regulated method

Comparative Study of the Aerodynamic Performance of the New MEXICO Rotor under Yaw Conditions

Development of a model to investigate the yaw behaviour of small horizontal axis wind turbines

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