scholarly journals Performance Characteristics of an Orthopter-Type Vertical Axis Wind Turbine in Shear Flows

2020 ◽  
Vol 10 (5) ◽  
pp. 1778
Author(s):  
Rudi Purwo Wijayanto ◽  
Takaaki Kono ◽  
Takahiro Kiwata
Keyword(s):  
Shear Flow ◽  
Wind Turbine ◽  
Azimuthal Angle ◽  
Vertical Axis ◽  
Uniform Flow ◽  
Performance Characteristics ◽  
Horizontal Shear ◽  
Vertical Axis Wind Turbine ◽  
Power Performance ◽  
Flow Case

To properly conduct a micro-siting of an orthopter-type vertical axis wind turbine (O-VAWT) in the built environment, this study investigated the effects of horizontal shear flow on the power performance characteristics of an O-VAWT by performing wind tunnel experiments and computational fluid dynamics (CFD) simulations. A uniform flow and two types of shear flow (advancing side faster shear flow (ASF-SF) and retreating side faster shear flow (RSF-SF)) were employed as the approaching flow to the O-VAWT. The ASF-SF had a higher velocity on the advancing side of the rotor. The RSF-SF had a higher velocity on the retreating side of the rotor. For each type of shear flow, three shear strengths (Γ = 0.28, 0.40 and 0.51) were set. In the ASF-SF cases, the power coefficients (Cp) were significantly higher than the uniform flow case at all tip speed ratios (λ) and increased with Γ. In the RSF-SF cases, CP increased with Γ. However, when Γ = 0.28, the CP was lower than the uniform flow case at all λ. When Γ = 0.51, the CP was higher than the uniform flow case except at low λ; however, it was lower than the ASF-SF case with Γ = 0.28. The causes of the features of CP were discussed through the analysis of the variation of blade torque coefficient, its rotor-revolution component and its blade-rotation component with azimuthal angle by using the CFD results for flow fields (i.e., horizontal velocity vectors, pressure and vorticity). These results indicate that a location where ASF-SFs with high Γ values dominantly occur is ideal for installing the O-VAWT.

scholarly journals Effect of Pitch Parameters on Aerodynamic Forces of a Straight-Bladed Vertical Axis Wind Turbine with Inclined Pitch Axes

2021 ◽  
Vol 11 (3) ◽  
pp. 1033
Author(s):  
Jia Guo ◽  
Timing Qu ◽  
Liping Lei
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Speed Ratio ◽  
Incline Angle ◽  
Asymmetric Distribution ◽  
Vertical Axis Wind Turbine ◽  
Power Performance ◽  
Aerodynamic Forces ◽  
Ansys Fluent ◽  
Pitch Regulation

Pitch regulation plays a significant role in improving power performance and achieving output control in wind turbines. The present study focuses on a novel, pitch-regulated vertical axis wind turbine (VAWT) with inclined pitch axes. The effect of two pitch parameters (the fold angle and the incline angle) on the instantaneous aerodynamic forces and overall performance of a straight-bladed VAWT under a tip-speed ratio of 4 is investigated using an actuator line model, achieved in ANSYS Fluent software and validated by previous experimental results. The results demonstrate that the fold angle has an apparent influence on the angles of attack and forces of the blades, as well as the power output of the wind turbine. It is helpful to further study the dynamic pitch regulation and adaptable passive pitch regulation of VAWTs. Incline angles away from 90° lead to the asymmetric distribution of aerodynamic forces along the blade span, which results in an expected reduction of loads on the main shaft and the tower of VAWTs.

Study on power performance for straight-bladed vertical axis wind turbine by field and wind tunnel test

2016 ◽  
Vol 90 ◽  
pp. 291-300 ◽  
Author(s):  
Qing'an Li ◽  
Takao Maeda ◽  
Yasunari Kamada ◽  
Junsuke Murata ◽  
Masayuki Yamamoto ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Tunnel Test ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Power Performance

Investigation of power performance and wake on a straight-bladed vertical axis wind turbine with field experiments

Energy ◽  
2017 ◽  
Vol 141 ◽  
pp. 1113-1123 ◽  
Author(s):  
Qing'an Li ◽  
Takao Maeda ◽  
Yasunari Kamada ◽  
Tatsuhiko Ogasawara ◽  
Alisa Nakai ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Field Experiments ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Power Performance

EXPERIMENTAL AND NUMERICAL EVALUATION OF PERFORMANCE OF A VARIABLE PITCH VERTICAL AXIS WIND TURBINE

2021 ◽  
pp. 1-14
Author(s):  
Owaisur Rahman Shah ◽  
Azfar Jamal ◽  
Talha Irfan Khan ◽  
Usama Waleed Qazi
Keyword(s):  
Wind Turbine ◽  
Azimuthal Angle ◽  
Research Work ◽  
Vertical Axis ◽  
Experimental Results ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Variable Pitch ◽  
Lift And Drag ◽  
Fixed Pitch

Abstract The research work depicts the study of the comparison of a 1kW Fixed Pitch Vertical Axis Wind Turbine (VAWT) and a Variable Pitch VAWT via analytical, numerical and experimental results. Being an emerging technology, wind turbine is becoming a source of attraction for the researchers. The VAWT in comparison to the Horizontal Axis Wind Turbine (HAWT), has shown numerous benefits. The fundamental purpose of this work is to maximize the output power and output torque of the wind turbine. For achieving an improved output, a novel and unique mechanism, termed as pitching mechanism, is employed that follows the variable pitch concept. The mathematical modelling was done for the straight blade variable pitch VAWT as well as for the fixed rotor. The four bar mechanism was developed, to execute the variable pitch mechanism, and implemented in the form of the CAD model. A scaled down 3D Model of the rotor was manufactured using 3D printing technique. The aerodynamic forces such as lift and drag were measured upon the rotor as per the testing on the rotor in the wind tunnel. CFD simulations were run for the fixed pitch as well as the variable pitch rotor. The transient analysis was performed for the azimuthal angle ranging from 0 to 360 degrees and for a pitch angle varying from +25 to-25 degrees in ANSYS software. The comparative study was undertaken, keeping in view the analytical, simulation and experimental results. A worthy agreement was observed between analytical, software and experimental results and a promising increase in power and torque was observed due the introduction of the variable pitch mechanism. The power produced by the variable pitch design showed a significant increase in the power production as compared to the fixed pitch design. The numerical and experimental values of cp for the variable pitch design were quite comparable.

Wind Tunnel Experiment on the Aerodynamic Interaction Between Vertical Axis Wind Turbine Pair

2021 ◽  
Author(s):  
Hao Su ◽  
Haoran Meng ◽  
Jia Guo ◽  
Timing Qu ◽  
Liping Lei
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Power Performance ◽  
Array Configuration ◽  
Aerodynamic Interaction ◽  
Positive Effect

Abstract Wind energy has attracted worldwide attention as a pollution-free and widely distributed renewable energy source. Increasing the power density by optimizing the arrangement of wind turbines has been a popular field of research in recent years. In the present work, a systematic study on the influence of array configuration on vertical axis wind turbines is made through wind tunnel experiments. Firstly, the power performance of an isolated vertical axis wind turbine at different tip speed ratios is tested as a benchmark of comparison. Multiple situations of two-turbine configurations are then tested and the results are compared with the isolated wind turbine. The power coefficient of the turbine pair increases by 34% when the turbines are 2.4 rotor diameters apart and rotate in the same direction. In the counter-rotating co-leeward case, it is demonstrated that the turbine pairs will have a positive effect on each other when they are separated by 2.1 rotor diameters to 2.4 rotor diameters. The lateral spacing between the counter-rotating co-windward turbine pair should be greater than 1.5 rotor diameters to avoid turbulence interference between the rotors.

Numerical Study of Vertical Axis Wind Turbine Rotor Configuration

2013 ◽  
Vol 859 ◽  
pp. 28-32
Author(s):  
Yi Mei ◽  
Jian Jun Qu ◽  
Xiao Ya Liu
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Numerical Study ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Radius Ratio ◽  
Speed Ratio ◽  
Wind Condition ◽  
Vertical Axis Wind Turbine ◽  
Power Performance

This paper presents a numerical study of a vertical axis wind rotor configuration. Below constant wind condition 8m/s, rotor power performance was investigated over variable turbine configurations. Illustrated by the simulation, increasing rotor cord to radius ratio or blade numbers will enhance the generation of vortexes and flow separation on blades, leading to the significant degradation of turbine performance. It can be conclude form the numerical analysis, a vertical axis wind turbine with high height to radius ratio applied in urban areas experienced better performance when operating in optimal tip speed ratio, with rotor cord to radius ratio between 0.2 and 0.4 and blade number of 3 or 4.

scholarly journals A Study of a Darrieus Vertical Axis Wind Turbine with a guiding nozzle

2020 ◽  
Vol 207 ◽  
pp. 02011
Author(s):  
Valentin Obretenov ◽  
Rossen Tliev
Keyword(s):  
Experimental Study ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Pitch Angle ◽  
Vertical Axis ◽  
Performance Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Pilot Studies ◽  
Generalized Characteristics ◽  
Turbine Model

This paper presents the results from an experimental study of a Vertical Axis Wind turbine model with a guiding nozzle. The geometry of the nozzle is synthesized by an original methodology. The performance characteristics of the turbine are investigated when changing the number of the blades and their pitch angle. The obtained results allow us to generate generalized characteristics that can be used in the design of new turbines of this type. The results of the pilot studies showing higher efficiency than the classical Darrieus wind turbines (up to 50 % which is close to the Betz limit).

The Analysis of Power Performance for Small H-Vertical Axis Wind Turbine

2013 ◽  
Vol 655-657 ◽  
pp. 37-42
Author(s):  
Ran Hui Liu
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Simulation Method ◽  
Aerodynamic Performance ◽  
Performance Curve ◽  
Vertical Axis Wind Turbine ◽  
Power Performance ◽  
Power Generator ◽  
Wind Power Generator ◽  
Volume Method

This paper mainly aims to get rotor aerodynamic performance curve and has studied the matching between the rotor and generator based on the numerical simulation method of the computational fluid dynamics, using the finite volume method to calculate the pneumatic performance of H-type wind power generator, so as to provide guidance for the power control of the small h-vertical axis wind turbine.

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