scholarly journals Numerical Research on the Vortex Center on the Forward-Swept 3-D Wind Turbine Blades at Low Rotational Speed

2018 ◽  
Vol 12 (12) ◽  
pp. 80
Author(s):  
Sutrisno . ◽  
Setyawan Bekti Wibowo ◽  
Sigit Iswahyudi
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Cfd Simulation ◽  
Velocity Ratio ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Leading Edge ◽  
Vortex Center ◽  
Wind Turbine Blades ◽  
Horizontal Axis Wind Turbine

This paper studies the CFD simulation of forward three-dimensional (3-D) horizontal axis wind turbine (HAWT) blades. Using logarithmic grid and Q-criterion to learn the vortex dynamics around the blades at low rotational speed. The computational fluid dynamics (CFD) simulation uses Q-criterion to probe vortices and logarithmic grid to emphasize the micro-gridding effect of the turbulent boundary layer. The visualization & measurement of the simulation results give the coefficient of pressure (Cp). For forward 3-D wind turbine blade, at low rotational speed, the strongly accelerated laminar region surrounds the lower blade, and the decelerated tip blade region coalesce each other give rise to a reverse limiting streamline, eroding the laminar region further until a little is left on the tip of the blade. The "reverse limiting streamline" grows inward radially, the area is narrowing closing to the leading edge of the blade tip. The second side of the rolled-up vortex appears the velocity ratio (Uc/Ulocal) of the second vortices are higher than the main vortex cores. For radius R=1.547 m, U=12 m/s, at 210 RPM, CL and CD values reach a maximum with fully laminar tip conditions. While at 120 RPM, the CL and CD values reach a minimum in the absence of laminar tips. The results show the detailed vortex dynamic pattern surround the blades, give more understanding to design laminar 3-D blade toward a noiseless wind turbine system.

scholarly journals CFD simulation on wind turbine blades with leading edge erosion

2021 ◽  
pp. 579-593
Author(s):  
Yan Wang ◽  
Liang Wang ◽  
Chenglin Duan ◽  
Jian Zheng ◽  
Zhe Liu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Leading Edge ◽  
Wind Turbine Blades

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.

Application of Tubercles in Wind Turbine Blades: A Review

2017 ◽  
Vol 867 ◽  
pp. 254-260 ◽  
Author(s):  
Vivek V. Kumar ◽  
Dilip A. Shah
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Fossil Fuels ◽  
Turbine Blades ◽  
Leading Edge ◽  
Electrical Energy ◽  
Humpback Whale ◽  
Wind Turbine Blades ◽  
Horizontal Axis Wind Turbine ◽  
Turbulent Fluid Flow

Due to the rapid depletion of conventional energy resources like fossil fuels and their harmful effects on the environment, there is an urgent need to seek alternative and sustainable energy sources. Wind energy is considered as one of the efficient source of energy which can be converted to useful form of energy like electrical energy. Though the field of wind engineering has developed in the recent era there is still scope for improvement in the effective utilization of energy. Energy efficiency in wind turbine is largely determined by the aerodynamics of the turbine blades and the characteristics of the turbulent fluid flow. The objective of this paper is to have a review on the improvement of Horizontal Axis Wind Turbine (HAWT) blade design by incorporating biomimetics into blades. Biomimetics is the field of science in which we adapt designs from nature to solve modern problems. The morphology of the wing-like flipper of the humpback whale (Megaptera novaeangliae) has potential for aerodynamic applications. Instead of straight leading edges like that of conventional hydrofoils, the humpback whale flipper has a number of sinusoidal rounded bumps, called tubercles arranged periodically along the leading edge. The presence of tubercles modifies the flow over the blade surface, creating vortices between the tubercles. These vortices interact with the flow over the tubercle and accelerate that flow, helping to maintain a partially attached boundary layer. This aerodynamic effect can delay stall to higher angles of attack, increase lift and reduce drag compared to the post-stall condition of conventional airfoils. The modified airfoil is characterized by a superior lift/drag ratio (L/D ratio) due to greater boundary layer attachment from vortices energizing the boundary layer.

scholarly journals The Rolled-up and Tip Vortices Studies in the CFD Model of the 3-D Swept-Backward Wind Turbine Blades

2017 ◽  
Vol 11 (12) ◽  
pp. 118 ◽  
Author(s):  
Sutrisno . ◽  
Deendarlianto . ◽  
Tri Agung Rochmat ◽  
Indarto . ◽  
Setyawan Bekti Wibowo ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Tip Vortex ◽  
Dynamics Simulation ◽  
Vortex Center ◽  
Wind Turbine Blades ◽  
Detailed Measurement ◽  
Vortex Effect ◽  
Strong Vortex

In this paper, the method to analyze of vortex dynamics simulation of 3-D (three dimensional) backward wind turbine blades is introduced, consisted of flow visualization part and detailed measurement part. With this method, one could explain visually and by calculation the role of 3-D flow vortex mechanism patterns on 3-D backward wind turbine blade, the interchange between kinetic and potential energies, the utilization of very strong vortex, which could lose energy, generate lift, and produce tangential mechanical power. The method could be elucidated by analyzing the appearance of rolled-up vortex effect on the 3-D backward wind turbine blades. A sharp pointed backward blade, generally has a weak tip vortex, may generate a second weak vortex center, and appears due to the rolled-up vortex effect, which is quite difficult to identify. The weakness of tip vortex makes the sharp pointed blade more efficient to exchange energy. Blunt backward turbine blades generally have a strong vortex center, a tip vortex; which in the form of a vortex core. Due to the rolled-up vortex effect, it could generate a second weak vortex center that is clearly visible. 

The Shape and Performance of Hand-Carved Small Wind Turbine Blades

2009 ◽  
Vol 33 (3) ◽  
pp. 299-304 ◽  
Author(s):  
P. D. Clausen ◽  
P. Freere ◽  
P. Peterson ◽  
S.V.R. Wilson ◽  
D.H. Wood
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Design Parameters ◽  
Surface Model ◽  
High Definition ◽  
Wind Turbine Blades ◽  
Horizontal Axis Wind Turbine ◽  
Profile Shape ◽  
Design Values

This paper describes measurements of the shape of a 900 mm long, hand-carved timber blade for a 500 W three-bladed horizontal axis wind turbine. Four blades were hand-carved in Nepal by reference to a master blade cut in Australia on a numerically controlled milling machine. A high definition three-dimensional scanner was used to determine the surface of one hand-carved blade as a series of profiles at 50 mm intervals along the blade's length. A surface model generated from these profiles was compared to the designed blade shape in terms of the three fundamental blade design parameters: chord, twist, and profile shape. The measured twist and chord were less that the design values, particularly in the hub region. This is consistent with the poor starting performance of the turbine when mounted with the remaining hand-carved blades. Assessment of the differences in profile shape would require a detailed computational analysis, which has not been undertaken.

Leading edge erosion of wind turbine blades: Understanding, prevention and protection

2021 ◽  
Vol 169 ◽  
pp. 953-969
Author(s):  
Leon Mishnaevsky ◽  
Charlotte Bay Hasager ◽  
Christian Bak ◽  
Anna-Maria Tilg ◽  
Jakob I. Bech ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Leading Edge ◽  
Wind Turbine Blades

Experimental investigations of flow over NACA airfoils 0021 and 4412 of wind turbine blades with and without Tubercles

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Critical Region ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Wind Turbine Blades

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.

Sign in / Sign up

Export Citation Format

Share Document