A comparative study of various inflow boundary conditions and turbulence models for wind turbine wake predictions

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840038 ◽  
Author(s):  
Lin-Lin Tian ◽  
Ning Zhao ◽  
Yi-Lei Song ◽  
Chun-Ling Zhu
Keyword(s):  
Boundary Conditions ◽  
Wind Turbine ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Wake Flow ◽  
Horizontal Axis Wind Turbine ◽  
Actuator Disc ◽  
Text Model ◽  
Simulation Results ◽  
Turbine Wake

This work is devoted to perform systematic sensitivity analysis of different turbulence models and various inflow boundary conditions in predicting the wake flow behind a horizontal axis wind turbine represented by an actuator disc (AD). The tested turbulence models are the standard k–[Formula: see text] model and the Reynolds Stress Model (RSM). A single wind turbine immersed in both uniform flows and in modeled atmospheric boundary layer (ABL) flows is studied. Simulation results are validated against the field experimental data in terms of wake velocity and turbulence intensity.

Numerical Simulation for Wind Turbine Wake and Effects From Different Atmospheric Boundary Conditions

2016 ◽  
Author(s):  
Peng Zhou ◽  
Xiuling Wang
Keyword(s):  
Boundary Conditions ◽  
Wind Turbine ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Wake Flow ◽  
Dynamics Simulation ◽  
Experiment Data ◽  
Eddy Simulation ◽  
Turbine Wake ◽  
Wind Turbine Wake

This research focuses on the computational fluid dynamics simulation of near wind turbine wake. Three dimensional wind turbine model is built based on S809 airfoil data [1]. Three different turbulence models are used and compared. They are Realizable k-ε model, SST k-ω model, and Large Eddy Simulation (LES) model. The simulation results from different turbulence models are compared with the NREL Phase VI experiment data. Different boundary conditions, including neutral and unstable conditions, were adopted in the simulation to analyze their influence on wake flow. Updraft and downdraft are considered in this part. Overall numerical results match well with the experiment data. The discussion also compares wind turbine wake under different atmospheric boundary conditions.

scholarly journals Three-Dimensional Wind Field Construction and Wind Turbine Siting in an Urban Environment

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 137 ◽  
Author(s):  
Mingrui Liu ◽  
Xiuling Wang
Keyword(s):  
Wind Turbine ◽  
Urban Environment ◽  
Wind Field ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Urban Environments ◽  
Urban Region ◽  
Wind Flow ◽  
Simulation Results

Three-dimensional urban wind field construction plays an important role not only in the analysis of pedestrian levels of comfort but also in the effectiveness of harnessing wind energy in an urban environment. However, it is challenging to accurately simulate urban wind flow due to the complex land use in urban environments. In this study, a three-dimensional numerical model was developed for urban wind flow construction. To obtain an accurate urban wind field, various turbulence models, including the Reynolds stress model (RSM), k-ω shear stress transport (SST), realizable k-ε, and (Re-Normalisation Group (RNG) k-ε models were tested. Simulation results were compared with experimental data in the literature. The RSM model showed promising potential in simulating urban wind flow. The model was then adopted to simulate urban wind flow for Purdue University Northwest, which is located in the Northwest Indiana urban region. Based on the simulation results, the optimal location was identified for urban wind turbine siting.

scholarly journals Numerical Study of Nacelle Wind Speed Characteristics of a Horizontal Axis Wind Turbine under Time-Varying Flow

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3993 ◽  
Author(s):  
Xiaodong Wang ◽  
Yunong Liu ◽  
Luyao Wang ◽  
Lin Ding ◽  
Hui Hu
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Wake Flow ◽  
Horizontal Axis Wind Turbine ◽  
Inlet Flow ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Speed Condition ◽  
Simulation Results

Nacelle wind speed transfer function (NTF) is usually used for power prediction and operational control of a horizontal axis wind turbine. Nacelle wind speed exhibits high instability as it is influenced by both incoming flow and near wake of a wind turbine rotor. Enhanced understanding of the nacelle wind speed characteristics is critical for improving the accuracy of NTF. This paper presents Reynolds-averaged Navier–Stokes (RANS) simulation results obtained for a multi-megawatt wind turbine under both stable and dynamic incoming flows. The dynamic inlet wind speed varies in the form of simplified sinusoidal and superposed sinusoidal functions. The simulation results are analyzed in time and frequency domains. For a stable inlet flow, the variation of nacelle wind speed is mainly influenced by the blade rotation. The influence of wake flow shows high frequency characteristics. The results with stable inlet flow show that the reduction of the nacelle wind speed with respect to the inlet wind speed is overestimated for low wind speed condition, and underestimated for high wind speed condition. Under time-varing inflow conditions, for the time scale and fluctuation amplitude subject to the International Electrotechnical Commission (IEC) standard, the nacelle wind speed is mainly influenced by the dynamic inflow. The variation of inflow can be recovered by choosing a suitable low pass filter. The work in this paper demonstrates the potential for building accurate NTF based on Computational Fluid Dynamics (CFD) simulations and signal analysis.

scholarly journals Estimation of wind turbine blade aerodynamic performances computed using different numerical approaches

2018 ◽  
Vol 45 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Jelena Svorcan ◽  
Ognjen Pekovic ◽  
Toni Ivanov
Keyword(s):  
Wind Turbine ◽  
Thrust Force ◽  
Turbulence Models ◽  
Turbine Rotor ◽  
Momentum Balance ◽  
Horizontal Axis Wind Turbine ◽  
Ansys Fluent ◽  
Force Coefficients ◽  
Aerodynamic Performances ◽  
Numerical Approaches

Although much employed, wind energy systems still present an open, contemporary topic of many research studies. Special attention is given to precise aerodynamic modeling performed in the beginning since overall wind turbine performances directly depend on blade aerodynamic performances. Several models different in complexity and computational requirements are still widely used. Most common numerical approaches include: i) momentum balance models, ii) potential flow methods and iii) full computational fluid dynamics solutions. Short explanations, reviews and comparison of the existing computational concepts are presented in the paper. Simpler models are described and implemented while numerous numerical investigations of isolated horizontal-axis wind turbine rotor consisting of three blades have also been performed in ANSYS FLUENT 16.2. Flow field is modeled by Reynolds Averaged Navier-Stokes (RANS) equations closed by two different turbulence models. Results including global parameters such as thrust and power coefficients as well as local distributions along the blade obtained by different models are compared to available experimental data. Presented results include fluid flow visualizations in the form of velocity contours, sectional pressure distributions and values of power and thrust force coefficients for a range of operational regimes. Although obtained numerical results vary in accuracy, all presented numerical settings seem to slightly under- or over-estimate the global wind turbine parameters (power and thrust force coefficients). Turbulence can greatly affect the wind turbine aerodynamics and should be modeled with care.

scholarly journals Numerical simulation of icing effect on aerodynamic characteristics of a wind turbine blade

2021 ◽  
Vol 25 (6 Part B) ◽  
pp. 4643-4650
Author(s):  
Yan Li ◽  
Lei Shi ◽  
Wen-Feng Guo ◽  
Kotaro Tagawa ◽  
Bin Zhao
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Aerodynamic Characteristics ◽  
Wind Turbine Blade ◽  
Horizontal Axis Wind Turbine ◽  
Ambient Temperatures ◽  
Research Findings ◽  
Simulation Results ◽  
Lift And Drag ◽  
Lift And Drag Coefficient

Icing accretion on wind turbine will degrade its performance, resulting in reduction of output power and even leading to accidents. For solving this problem, it is necessary to predict the icing type and shape on wind turbine blade, and evaluate the variation of aerodynamic characteristics. In this paper the icing types and shapes in presence of airfoil, selected from blade of 1.5 MW horizontal-axis wind turbine, are simulated under different ambient temperatures and icing time lengths. Based on the icing simulation results, the aerodynamic characteristics of icing airfoils are simulated, including lift and drag coefficient, lift-drag ratio, etc. The simulation results show that the glaze ice with two horns presents on airfoil under high ambient temperature such as -5?C. When ambient temperatures are low, such as -10?C and -15?C, the rime ices with streamline profiles present on the airfoil. With increase in icing time the lift forces and coefficients decrease, and the drag ones increase. According to the variations of lift-drag ratios of icing airfoil, the aerodynamic performance of airfoil deteriorates in the presence of icing. The glaze ice has great effect on aerodynamic characteristics of airfoil. The research findings lay theoretical foundation for icing wind tunnel experiment.

Aerodynamic Characteristics of Horizontal Axis Wind Turbine With Archimedes Spiral Blade

2013 ◽  
Author(s):  
Kyung Chun Kim ◽  
Yoon Kee Kim ◽  
Ho Seong Ji ◽  
Jook Ho Beak ◽  
Rinus Mieremet
Keyword(s):  
Steady State ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Aerodynamic Characteristics ◽  
Wake Flow ◽  
Power Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Mean Velocity ◽  
Archimedes Spiral ◽  
Spiral Blade

To investigate the aerodynamic characteristics of an Archimedes spiral wind turbine for urban-usage, both experimental and numerical studies were carried out. The Archimedes spiral blade was designed to produce wind power using drag and lift forces on the blade together. Instantaneous velocity fields were measured by two-dimensional PIV method in the near field of the blade. Mean velocity profiles were compared to those predicted by the steady state and unsteady state CFD simulation. It was found that the interaction between the wake flow at the rotor downstream and the induced velocity due to the tip vortices were strongly affected by the wind speed and resulting rotational speed of the blade. PIV measurements revealed the presence of dominant vertical structures at downstream the hub and near the blade tip. Unsteady CFD simulation results agreed well with those of PIV experiments than the steady state analysis. The power coefficient (Cp) obtained by CFD simulation demonstrated that the new type of wind turbine produced about 0.25, relatively high value compared to other types of urban-usage wind turbine.

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