Numerical investigation of active flow control with co-flowing jet in a horizontal axis wind turbine

2020 ◽  
pp. 0309524X2096139
Author(s):  
Fangrui Shi ◽  
Yingqiao Xu ◽  
Xiaojing Sun
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Performance Enhancement ◽  
Active Flow Control ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Suction Surface ◽  
Horizontal Axis Wind Turbine ◽  
Momentum Coefficient ◽  
Active Flow

In this paper, a three-dimensional numerical simulation of the aerodynamic performance of a horizontal axis wind turbine (HAWT) whose blades are equipped with a new active flow control concept called Co-Flowing Jet (CFJ) is carried out. Numerical results show that the use of CFJ over the blade suction surface can effectively delay flow separation, thus improving the net torque and power output of HAWT. Besides, this increment in the net power produced by the turbine is considerably higher than the power consumed by the CFJ. Thus, the overall efficiency of the HAWT can be greatly increased. Furthermore, influences of different CFJ operating parameters including location of injection port, jet momentum coefficient and slot length on the performance enhancement of a HAWT are also systematically studied and the optimal combination of these parameters to obtain the best possible turbine efficiency throughout a range of different wind speeds has been identified.

High Efficiency Wind Turbine Using Co-Flow Jet Active Flow Control

2021 ◽  
Author(s):  
Kewei Xu ◽  
Gecheng Zha
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Flow Separation ◽  
Power Output ◽  
Pitch Angle ◽  
Active Flow Control ◽  
Horizontal Axis Wind Turbine ◽  
Negative Power ◽  
Freestream Velocity ◽  
Active Flow

Abstract This paper applies Co-flow Jet (CFJ) active flow control airfoil to a NREL horizontal axis wind turbine for power output improvement. CFJ is a zero-net-mass-flux active flow control method that dramatically increases airfoil lift coefficient and suppresses flow separation at a low energy expenditure. The 3D Reynolds Averaged Navier-Stokes (RANS) equations with one-equation Spalart-Allmaras (SA) turbulence model are solved to simulate the 3D flows of the wind turbines. The baseline wind turbine is the NREL 10.06m diameter phase VI wind turbine and is modified to a CFJ blade by implementing CFJ along the span. The baseline wind turbine performance is validated with the experiment at three wind speeds, 7m/s, 15m/s, and 25m/s. The predicted blade surface pressure distributions and power output agree well with the experimental measurements. The study indicates that the CFJ can enhance the power output at the condition where angle of attack is increased to the level that conventional wind turbine is stalled. At the speed of 7m/s that the NREL turbine is designed to achieve the optimum efficiency at the pitch angle of 3°, the CFJ turbine does not increase the power output. When the pitch angle is reduced by 13° to −10°, the baseline wind turbine is stalled and generates negative power output at 7m/s. But the CFJ wind turbine increases the power output by 12.3% assuming CFJ fan efficiency of 80% at the same wind speed. This is an effective method to extract more power from the wind at all speeds. It is particularly useful at low speeds to decrease cut-in speed and increase power output without exceeding the structure limit. At the freestream velocity of 15m/s and the CFJ momentum coefficient Cμ of 0.23, the net power output is increased by 207.7% assuming the CFJ fan efficiency of 80%, compared to the baseline wind turbine due to the removal of flow separation. The CFJ wind turbine appears to open a door to a new area of wind turbine efficiency improvement and adaptive control for optimal loading.

scholarly journals Study and Design of a Horizontal Axis Wind Turbine (0.5 kW) Using Software Solid Works

2021 ◽  
pp. 1-17
Author(s):  
Hagninou E. V. Donnou ◽  
Drissa Boro ◽  
Jean Noé Fabiyi ◽  
Marius Tovoeho ◽  
Aristide B. Akpo
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Wedge Angle ◽  
Three Dimensional ◽  
Synchronous Generator ◽  
Horizontal Axis ◽  
Geometrical Shape ◽  
Horizontal Axis Wind Turbine ◽  
Horizontal Axis Wind Turbines ◽  
Lift And Drag

In the present work, the study and design of a horizontal axis wind turbine suitable for the Cotonou site were investigated on the coast of Benin. A statistical study using the Weibull distribution was carried out on the hourly wind data measured at 10 m from the ground by the Agency for Air Navigation Safety in Africa and Madagascar (ASECNA) over the period from January 1981 to December 2014. Then, the models, techniques, tools and approaches used to design horizontal axis wind turbines were presented and the wind turbine components characteristics were determined. The numerical design and assembly of these components were carried out using SolidWorks software. The results revealed that the designed wind turbine has a power of 571W. It is equipped with a permanent magnet synchronous generator and has three aluminum blades with NACA 4412 biconvex asymmetrical profile. The values obtained for the optimum coefficient of lift and drag are estimated at 1.196 and 0.0189 respectively. The blades are characterised by an attack optimum angle estimated at 6° and the wedge angle at 5°. Their length is 2.50 m and the maximum thickness is estimated at 0.032 m for a rope length of 0.27 m. The wind turbine efficiency is 44%. The computer program designed on SolidWorks gives three-dimensional views of the geometrical shape of the wind turbine components and their assembly has allowed to visualize the compact shape of the wind turbine after export via its graphical interface. The energy quantity that can be obtained from the wind turbine was estimated at 2712,718 kWh/year. This wind turbine design study is the first of its kind for the study area. In order to reduce the technological dependence and the import of wind energy systems, the results of this study could be used to produce lower cost wind energy available on our study site.

Influence of microcylinders with different vibration laws on the flow control effect of a horizontal axis wind turbine

Wind Energy ◽  
2019 ◽  
Vol 22 (12) ◽  
pp. 1800-1824
Author(s):  
Ying Wang ◽  
Gaohui Li ◽  
Dahai Luo ◽  
Diangui Huang
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Control Effect ◽  
Horizontal Axis Wind Turbine

scholarly journals Investigation of an Innovative Rotor Modification for a Small-Scale Horizontal Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2649 ◽  
Author(s):  
Artur Bugała ◽  
Olga Roszyk
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Airflow Distribution

This paper presents the results of the computational fluid dynamics (CFD) simulation of the airflow for a 300 W horizontal axis wind turbine, using additional structural elements which modify the original shape of the rotor in the form of multi-shaped bowls which change the airflow distribution. A three-dimensional CAD model of the tested wind turbine was presented, with three variants subjected to simulation: a basic wind turbine without the element that modifies the airflow distribution, a turbine with a plano-convex bowl, and a turbine with a centrally convex bowl, with the hyperbolic disappearance of convexity as the radius of the rotor increases. The momentary value of wind speed, recorded at measuring points located in the plane of wind turbine blades, demonstrated an increase when compared to the base model by 35% for the wind turbine with the plano-convex bowl, for the wind speed of 5 m/s, and 31.3% and 49% for the higher approaching wind speed, for the plano-convex bowl and centrally convex bowl, respectively. The centrally convex bowl seems to be more appropriate for higher approaching wind speeds. An increase in wind turbine efficiency, described by the power coefficient, for solutions with aerodynamic bowls was observed.

scholarly journals Performance Enhancement of a Full-Scale Vertical Tail Model Equipped with Active Flow Control

2015 ◽  
Author(s):  
Edward A. Whalen ◽  
Doug S. Lacy ◽  
John C. Lin ◽  
Marlyn Y. Andino ◽  
Anthony E. Washburn ◽  
...  
Keyword(s):  
Flow Control ◽  
Performance Enhancement ◽  
Active Flow Control ◽  
Full Scale ◽  
Active Flow

Iterative Learning Active Flow Control Applied to a Compressor Stator Cascade With Periodic Disturbances

2015 ◽  
Author(s):  
Simon J. Steinberg ◽  
Rudibert King ◽  
Marcel Staats ◽  
Wolfgang Nitsche
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Pressure Sensors ◽  
Iterative Learning ◽  
Suction Surface ◽  
Periodic Disturbances ◽  
Control Command ◽  
Detonation Engine ◽  
Active Flow ◽  
The Impact

This contribution presents the capability of iterative learning active flow control to decrease the impact of periodic disturbances in an experimental compressor stator cascade with sidewall actuation. The periodic disturbances of the individual passage flows are generated by a damper flap device that is located downstream of the trailing edges of the blades. These mimic the throttling effect of periodically closed combustion tubes in a pulsed detonation engine. For the purpose of rejecting this disturbance the passage flow is manipulated by fluidic actuators that introduce an adjustable amount of pressurized air through slots in the sidewalls of the cascade. Pressure sensors that are mounted flush to the suction surface of the middle blade provide information on the current flow situation. This data is fed back in real-time to an optimal iterative learning controller. By learning from period to period the controller modifies the actuation amplitude such that, eventually, a control command trajectory is calculated that reduces the impact of the periodic disturbance on the flow in an optimal manner.

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