scholarly journals Numerical Framework for Aerodynamic Characterization of Wind Turbine Airfoils: Application to Miniature Wind Turbine WiRE-01

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5612
Author(s):  
Tristan Revaz ◽  
Mou Lin ◽  
Fernando Porté-Agel
Keyword(s):  
Wind Turbine ◽  
Computational Cost ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Eddy Simulation ◽  
Turbulent Inflow ◽  
Inflow Turbulence ◽  
Volume Method ◽  
Turbine Airfoils

A numerical framework for the aerodynamic characterization of wind turbine airfoils is developed and applied to the miniature wind turbine WiRE-01. The framework is based on a coupling between wall-resolved large eddy simulation (LES) and application of the blade element momentum theory (BEM). It provides not only results for the airfoil aerodynamics but also for the wind turbine, and allows to cover a large range of turbine operating conditions with a minimized computational cost. In order to provide the accuracy and the flexibility needed, the unstructured finite volume method (FVM) and the wall-adapting local eddy viscosity (WALE) model are used within the OpenFOAM toolbox. With the purpose of representing the turbulence experienced by the blade sections of the turbine, a practical turbulent inflow is proposed and the effect of the inflow turbulence on the airfoil aerodynamic performance is studied. It is found that the consideration of the inflow turbulence has a strong effect on the airfoil aerodynamic performance. Through the application of the framework to WiRE-01 miniature wind turbine, a comprehensive characterization of the airfoil used in this turbine is provided, simplifying future studies. In the same time, the numerical results for the turbine are validated with experimental results and good consistency is found. Overall, the airfoil and turbine designs are found to be well optimized, even if the effective angle of attack of the blades should be reduced close to the hub.

Performance Characterization of a Twin Scroll Volute for Turbocharging Applications

2018 ◽  
Author(s):  
Carlo Cravero ◽  
Mario La Rocca ◽  
Andrea Ottonello
Keyword(s):  
Experimental Data ◽  
Scientific Literature ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Automatic Design ◽  
Cfd Model ◽  
Radial Turbine ◽  
Wide Range ◽  
Partial Admission

The use of twin scroll volutes in radial turbine for turbocharging applications has several advantages over single passage volute related to the engine matching and to the overall compactness. Twin scroll volutes are of increasing interest in power unit development but the open scientific literature on their performance and modelling is still quite limited. In the present work the performance of a twin scroll volute for a turbocharger radial turbine are investigated in some detail in a wide range of operating conditions at both full and partial admission. A CFD model for the volute have been developed and preliminary validated against experimental data available for the radial turbine. Then the numerical model has been used to generate the database of solutions that have been investigated and used to extract the performance. Different parameters and indices are introduced to describe the volute aerodynamic performance in the wide range of operating conditions chosen. The above parameters can be used for volute development or matching with a given rotor or efficiently implemented in automatic design optimization strategies.

scholarly journals Efficient contribution of partially tip cascaded horizontal-axis wind turbine

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401989211
Author(s):  
Deyaa Nabil Elshebiny ◽  
Ali AbdelFattah Hashem ◽  
Farouk Mohammed Owis
Keyword(s):  
Wind Turbine ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Horizontal Axis ◽  
National Renewable Energy Laboratory ◽  
Horizontal Axis Wind Turbine ◽  
Ansys Fluent ◽  
Knowing That ◽  
Turbine Performance ◽  
Blade Tip

This article introduces novel blade tip geometric modification to improve the aerodynamic performance of horizontal-axis wind turbine by adding auxiliary cascading blades toward the tip region. This study focuses on the new turbine shape and how it enhances the turbine performance in comparison with the classical turbine. This study is performed numerically for National Renewable Energy Laboratory Phase II (non-optimized wind turbine) taking into consideration the effect of adding different cascade configurations on the turbine performance using ANSYS FLUENT program. The analysis of single-auxiliary and double-auxiliary cascade blades has shown an impact on increasing the turbine power of 28% and 76%, respectively, at 72 r/min and 12.85 m/s of wind speed. Knowing that the performance of cascaded wind turbine depends on the geometry, solidity and operating conditions of the original blade; therefore, these results are not authorized for other cases.

Operational Risk Assessment of Wind Turbine Structures Using Probabilistic Analysis of Aerodynamically Induced Vibrations

2011 ◽  
Author(s):  
Antonio Velazquez ◽  
R. Andrew Swartz
Keyword(s):  
Risk Assessment ◽  
Wind Turbine ◽  
Numerical Solution ◽  
Vortex Shedding ◽  
Element Model ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Force Transmission ◽  
Resistance Risk ◽  
Structural Resistance

The study of efficiency and safety for wind turbine structures under variable operating conditions is increasingly important for wind turbine design. Optimum aerodynamic performance of a wind turbine demands that serviceability effects and ultimate strength loads remain under safety design limits. From the perspective of wind turbine efficiency, variations in wind speed causes bluffing effects and vortex shedding that lead to vibration intensities in the longitudinal and transversal direction that can negatively impact aerodynamic performance of the turbine. From the perspective of wind turbine safety, variations in loading may lead to transient internal loads that threaten the safety of the structure. Inertial effects and asynchronous delays on rotational-force transmission may generate similar hazards. Monitoring and controlling displacement limits and load demands at critical tower locations can improve the efficiency of wind power generation, not to mention the structural performance of the turbine from both a strength and serviceability point of view. In this study, a probabilistic monitoring approach is developed to measure the response of the combined tower/nacelle/blade system to stochastic loading, estimate peak demand, and compare that demand to building code-derived estimates of structural resistance. Risk assessment is performed for the effects of along and across-wind forces in a framework of quantitative risk analysis with the goal of developing a near real-time estimate of structural risk that may be used to monitor safety and serviceability of the structure as well as regulate the aggressiveness of the controller that commands the blade angle of attack. To accomplish this goal, a numerical simulation of the aerodynamic performance of a wind turbine (including blades, the nacelle and the tower) is analyzed to study the interaction between the structural system and incoming flow. A model based on distributed-stationary random wind load profile for the combined along-wind and across-wind responses is implemented in Matlab to simulate full aero-elastic dynamic analysis to simulate tower with nacelle, hub, rotor and tower substructures. Self-weight, rotational, and axial effects of the blades, as well as lateral resistance of substructure elements are incorporated in the finite element model, including vortex-shedding effects on the wake zone. Reliability on the numerical solution is inspected on the tower structure by comparing the numerical solution with established experimental-analytical procedures.

scholarly journals Role of Inflow Turbulence and Surrounding Buildings on Large Eddy Simulations of Urban Wind Energy

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5208 ◽  
Author(s):  
Giulio Vita ◽  
Syeda Anam Hashmi ◽  
Simone Salvadori ◽  
Hassan Hemida ◽  
Charalampos Baniotopoulos
Keyword(s):  
Wind Energy ◽  
Geometric Model ◽  
Tall Buildings ◽  
Flow Patterns ◽  
Eddy Simulation ◽  
Turbulent Inflow ◽  
Positioning Strategy ◽  
Large Eddy ◽  
Inflow Turbulence ◽  
Mean Wind Speed

Predicting flow patterns that develop on the roof of high-rise buildings is critical for the development of urban wind energy. In particular, the performance and reliability of devices largely depends on the positioning strategy, a major unresolved challenge. This work aims at investigating the effect of variations in the turbulent inflow and the geometric model on the flow patterns that develop on the roof of tall buildings in the realistic configuration of the University of Birmingham’s campus in the United Kingdom (UK). Results confirm that the accuracy of Large Eddy Simulation (LES) predictions is only marginally affected by differences in the inflow mean wind speed and turbulence intensity, provided that turbulence is not absent. The effect of the presence of surrounding buildings is also investigated and found to be marginal to the results if the inflow is turbulent. The integral length scale is the parameter most affected by the turbulence characteristics of the inflow, while gustiness is only marginally influenced. This work will contribute to LES applications on the urban wind resource and their computational setup simplification.

scholarly journals Investigation into Yaw Motion Influence of Horizontal-Axis Wind Turbine on Wake Flow Using LBM-LES

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5248
Author(s):  
Weimin Wu ◽  
Xiongfei Liu ◽  
Jingcheng Liu ◽  
Shunpeng Zeng ◽  
Chuande Zhou ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Aerodynamic Characteristics ◽  
Angular Speed ◽  
Aerodynamic Performance ◽  
Tip Vortex ◽  
Wake Flow ◽  
Horizontal Axis Wind Turbine ◽  
Near Wake ◽  
Eddy Simulation ◽  
Sweep Surface

The dynamic yaw motion of the wind turbine will affect the overall aerodynamic performance of the impeller and the corresponding wake flow, but the current research on this issue is inadequate. Thus, it is very necessary to study the complicated near-wake aerodynamic behaviors during the yaw process and the closely related blade aerodynamic characteristics. This work utilized the multi-relaxation time lattice Boltzmann (MRT-LBM) model to investigate the integral aerodynamic performance characteristics of the specified impeller and the dynamic changes in the near wake under a sine yawing process, in which the normalized result is adopted to facilitate data comparison and understanding. Moreover, considering the complexity of the wake flows, the large eddy simulation (LES) and wall-adapting local eddy-viscosity (WALE) model are also used in this investigation. The related results indicate that the degree of stability of tip spiral wake in the dynamic yaw condition is inversely related to the absolute value of the change rate of yaw angular speed. When the wind turbine returns to the position with the yaw angle of 0 (deg) around, the linearized migration of tip vortex is changed, and the speed loss in the wake center is reduced at about the normalized velocity of 0.27, and another transverse expansion appeared. The directional inducing downstream of the impeller sweep surface for tip vortex is clearly reflected on the entering side and the exiting side. Additionally, the features of the static pressure on the blade surface and the overall aerodynamic effects of the impeller are also discussed, respectively.

Aerodynamic Performance of Preferred Wind Turbine Airfoils

2012 ◽  
Author(s):  
Horacio Perez-Blanco ◽  
Maureen McCaffrey
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Incidence Angle ◽  
Aerodynamic Performance ◽  
Blade Element Theory ◽  
Using Data ◽  
Simple Evaluation ◽  
Turbine Airfoils ◽  
Operational Range ◽  
Element Theory

To investigate possible increases of the capacity factor of wind turbines, six airfoils are chosen for evaluation, three based on high Cl, low Cd/Cl, and wide operational range, and three others simply based on low Cd. Aerodynamic performance of the chosen airfoils is projected for a 45 m radius turbine using Blade Element Theory (BET) as translated in an existing computer program. Even though the airfoils do not differ significantly in shape, their performance is projected to differ in turbine performance calculations, with some generating more power than others at the same wind speed and air density. The aerodynamic performance obtained with the numerically tested airfoils is compared to that of an actual wind turbine of equal dimensions. Wind speed and directional changes can be large, and assessing their effect is complicated. Using data from the literature, a simple evaluation of the effect of wind speed can be incorporated into the power curve, and shown to be dependent on the airfoil type. Directional changes could lead to reduced output power, but they are more significant for BEs close to the hub than to the tip. The optimal incidence angle calculated with the program shows little variability with wind speed for all airfoils.

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