Numerical Studies on the Effect of Cambered Airfoil Blades on Self-Starting of Vertical Axis Wind Turbine Part 2: NACA 0018 and NACA 63415

2015 ◽  
Vol 787 ◽  
pp. 245-249 ◽  
Author(s):  
Sivamani Seralathan ◽  
T. Micha Premkumar ◽  
S. Thangavel ◽  
G.P. Pradeep
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Lift Force ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Numerical Studies ◽  
Airfoil Blades ◽  
Torque Values ◽  
Naca 0012

NACA 0012 and NACA 4415 were discussed in Part 1 of the paper to study the capabilities of the airfoil blades by considering the effect of cambered airfoil blade on self-starting of vertical axis wind turbine. The numerical studies are carried out to identify self-starting capability of the airfoil using CFD analysis by studying the flow field over the vertical axis wind turbine blades. In this Part 2 paper, detailed numerical results of asymmetrical NACA 0018 and cambered airfoil NACA 63415 are presented. The lift force generated and the rotor torque induced varies with angle of attack. Based on the contours of static pressure and velocity distribution as well as based on the torque induced in the flow field over blade profiles, NACA 0018 is found to be better compared to cambered airfoil. Even though the lift force for cambered airfoils are higher, based on the rotor torque values, the wind turbine with asymmetrical airfoil blades NACA 0012 is better by 9.80% compared with NACA 4415 and 21.73% compared with NACA 63415. Self-starting issue can be addressed by proper selection of NACA blade profiles. By comparing the four airfoil blades in Part 1 and Part 2 of the papers, the asymmetrical NACA 0012 is found to be most suitable airfoil for self-starting the vertical axis wind turbine (VAWT).

Numerical Studies on the Effect of Cambered Airfoil Blades on Self-Starting of Vertical Axis Wind Turbine Part 1: NACA 0012 and NACA 4415

2015 ◽  
Vol 787 ◽  
pp. 250-254 ◽  
Author(s):  
T. Micha Premkumar ◽  
Sivamani Seralathan ◽  
T. Mohan ◽  
N.N.P. Saran Reddy
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
Static Pressure Distribution ◽  
Numerical Studies ◽  
Airfoil Blades ◽  
Torque Values ◽  
Naca 0012

This is Part-1 of the two-part paper in considering the effect of cambered airfoil blades on self-starting of vertical axis wind turbine. Part 1 reports the numerical studies on self-starting of vertical axis wind turbine with comparative studies involving NACA 0012 and cambered airfoil NACA 4415. Part 2 of the paper deals with numerical studies of NACA 0018 and cambered air foil NACA 63415. Darrieus type VAWT is attracting many researchers attention for its inherent advantages and its diversified applications. However, a disadvantage is when the rotor is stationary, no net rotational forces arises, even at high-wind speed. The principal advantage of the vertical axis format is their ability to accept wind from any direction without yawing mechanism. However, self-starting capability is the major drawbacks. Moreover, literatures based on computational analysis involving the cambered airfoil are few only. The objective of this present study is to select the suitable airfoil blades on self-starting of VAWT at low-Reynolds number. The numerical studies are carried out to identify self-starting capability of the airfoil using CFD analysis by studying the flow field over the vertical axis wind turbine blades. The commercial CFD code, ANSYS CFX 13.0© was used for the present studies. Initially, the flow over NACA 0012 was simulated and analyzed for different angles of attacks and similarly carried out for NACA 4415. The contours of static pressure distribution and velocity as well as the force and torque were obtained. Even though the lift force for cambered airfoil NACA 4415 is higher, based on the torque values of the above blade profiles, asymmetrical airfoil NACA 0012 is found to be appropriate for self-starring of VAWT.

Computational Analysis of Airfoil Merging and its Effect on Performance of Lift Based Vertical Axis Wind Turbine

2016 ◽  
Author(s):  
Akshay Basavaraj
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Vertical Axis Wind Turbine ◽  
Low Wind Speed ◽  
Naca 0012 ◽  
Selection Of

In regions of low wind speed, overcoming the starting torque of a Vertical Axis Wind Turbine (VAWT) becomes a challenge aspect. In order to overcome this adversity, careful selection of airfoils for the turbine blades becomes a priority. This paper tries to address the issue utilizing an approach wherein by observing the effect of merging two airfoils. Two airfoils which are of varying camber and thickness are merged and their aerodynamic characteristics are evaluated using the software XFOIL 6.96. For a variation in angle of attack from 0 to 90°, aerodynamic analysis is done in order to observe the behavior of one quarter of the entire VAWT cycle. An objective function is developed so as to observe the maximum possible torque generated by these airfoils at Reynolds number varying from 15,000–120,000. Due to change in the value of CL observed at Low Reynolds Number using commercial CFD softwares, multiple objective functions are utilized to observe the behavior over a range of Reynolds number. An experimental co-relation between the cut-in velocity and the lift-coefficient of the airfoils is developed in order to predict the cut-in velocity of the interpolated airfoils. The airfoils used for this paper are NACA 0012, NACA 0018, FX 66 S196, Clark Y (smooth), PT 40, SD 7032, A 18, SD 7080, SG 6043 and SG 6040.

scholarly journals Numerical Simulation of Aerodynamic Performance of Off-grid Small Vertical Axis Wind Turbine

2018 ◽  
Vol 53 ◽  
pp. 02004
Author(s):  
Qiuyun Mo ◽  
Jiabei Yin ◽  
Lin Chen ◽  
Weihao Liu ◽  
Li Jiang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Velocity Fields ◽  
Compact Model ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
Rotation Domain ◽  
Rng Turbulence Model

In this paper, a 2D off-grid small compact model of vertical axis wind turbine was established. The sliding grid technology, the RNG turbulence model and the Coupld algorithm was applied to simulate the unsteady value of the model's aerodynamic performance. Through the analysis on the flow field at difference moments, the rules about velocity fields, vortices distributions and the wind turbine's total torque were obtained. The results show that: the speed around wind turbine blades have obvious gradient, and the velocity distribution at different times show large differences in the computional domain. In the rotating domain vorticity is large. With away from the rotation domain, vorticity reduced quickly. In the process of rotating for vertical axis wind turbine, the wind turbine's total torque showed alternating positive and negative changes.

Hybrid Polymer Additive Manufacturing of a Darrieus Type Vertical Axis Wind Turbine Design to Improve Power Generation Efficiency

2016 ◽  
Author(s):  
Sourabh Deshpande ◽  
Nithin Rao ◽  
Nitin Pradhan ◽  
John L. Irwin
Keyword(s):  
Power Generation ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Blade Design ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
3D Printed

Utilizing the advantages of additive manufacturing methods, redesigning, building and testing of an existing integral Savonius / Darrieus “Lenz2 Wing” style vertical axis wind turbine is predicted to improve power generation efficiency. The current wind turbine blades and supports made from aluminum plate and sheet are limiting the power generation due to the overall weight. The new design is predicted to increase power generation when compared to the current design due to the lightweight spiral Darrieus shaped hollow blade made possible by 3D printing, along with an internal Savonius blade made from aluminum sheet and traditional manufacturing techniques. The design constraints include 3D printing the turbine blades in a 0.4 × 0.4 × 0.3 m work envelope while using a Stratasys Fortus 400mc and thus the wind turbine blades are split into multiple parts with dovetail joint features, when bonded together result in a 1.2 m tall working prototype. Appropriate allowance in the mating dovetail joints are considered to facilitate the fit and bonding, as well as angle, size and placement of the dovetail to maximize strength. The spiral shape and Darrieus style cross section of the blade that provides the required lift enabling it to rotate from the static condition are oriented laterally for 3D printing to maximize strength. The bonding of the dovetail joints is carried out effectively using an acetone solution dip. The auxiliary components of the wind turbine which include the center support pole, top and bottom support, and center Savonius blades are manufactured using lightweight aluminum. Design features are included in the 3D printed blade parts so that they can be assembled with the aluminum parts in bolted connections. Analysis of the 3D CAD models show that the hybrid aluminum and hollow 3D printed blade construction provides a 50% cost savings over a 3D printed fully solid blade design while minimizing weight and maximizing the strength where necessary. Analysis of the redesign includes a detailed weight comparison, structural strength and the cost of production. Results include linear static finite element analysis for the strength in dovetail joint bonding and the aluminum to 3D printed connections. Additional data reported are the time frame for the design and manufacturing of the system, budget, and an operational analysis of the wind turbine with concern for safety. Results are analyzed to determine the advantages in utilizing a hybrid additive manufacturing and aluminum construction for producing a more efficient vertical axis wind turbine. Techniques used in the production of this type of wind turbine blade are planned to be utilized in similar applications such as a lightweight hovercraft propeller blade design to be tested in future research projects.

Investigation of aerodynamic forces and flow field of an H-type vertical axis wind turbine based on bionic airfoil

Energy ◽  
2021 ◽  
pp. 122999
Author(s):  
Yanfeng Zhang ◽  
Zhiping Guo ◽  
Xinyu Zhu ◽  
Yuan Li ◽  
Xiaowen Song ◽  
...  
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbine ◽  
Aerodynamic Forces ◽  
Bionic Airfoil

scholarly journals Aerodynamics and Modal Analysis for the Combined Vane type Vertical Axis Wind Turbine

2018 ◽  
Vol 7 (4.38) ◽  
pp. 1395 ◽  
Author(s):  
Kadhim H. Suffer ◽  
Yassr Y. Kahtan ◽  
Zuradzman M. Razlan
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Mode Shapes ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Starting Torque

The present global energy economy suggests the use of renewable sources such as solar, wind, and biomass to produce the required power. The vertical axis wind turbine is one of wind power applications. Usually, when the vertical axis wind turbine blades are designed from the airfoil, the starting torque problem begins. The main objective of this research is to numerically simulate the combination of movable vanes of a flat plate with the airfoil in a single blade configuration to solve the starting torque problem. CFD analysis in ANSYS-FLUENT and structural analysis in ANSYS of combined blade vertical axis wind turbine rotor has been undertaken. The first simulation is carried out to investigations the aerodynamic characteristic of the turbine by using the finite volume method. While the second simulation is carried out with finite element method for the modal analysis to find the natural frequencies and the mode shape in order to avoid extreme vibration and turbine failure, the natural frequencies, and their corresponding mode shapes are studied and the results were presented with damping and without damping for four selected cases. The predicted results show that the static pressure drop across the blade increase in the active blade side because of the vanes are fully closed and decrease in the negative side because of the all the vanes are fully open. The combined blade helps to increase turbine rotation and so, thus, the power of the turbine increases. While the modal results show that until the 5th natural frequency the effect of damping can be neglected. The predicted results show agreement with those reported in the literature for VAWT with different blade designs.   

scholarly journals Design and 3D CFD Static Performance Study of a Two-Blade IceWind Turbine

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5356
Author(s):  
Hamdy Mansour ◽  
Rola Afify
Keyword(s):  
Wind Turbine ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Scale Model ◽  
Vertical Axis Wind Turbine ◽  
Performance Study ◽  
Static Performance ◽  
New Type ◽  
Torque Values ◽  
Static Torque

The IceWind turbine, a new type of Vertical Axis Wind Turbine, was proposed by an Iceland based startup. It is a product that has been featured in few published scientific research studies. This paper investigates the IceWind turbine’s performance numerically. Three-dimensional numerical simulations are conducted for the full scale model using the SST K-ω model at a wind speed of 15.8 m/s. The following results are documented: static torque, velocity distributions and streamlines, and pressure distribution. Comparisons with previous data are established. Additionally, comparisons with the Savonius wind turbine in the same swept area are conducted to determine how efficient the new type of turbine is. The IceWind turbine shows a similar level of performance with slightly higher static torque values. Vortices behind the IceWind turbine are confirmed to be three-dimensional and are larger than those of Savonius turbine.

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