scholarly journals Design and Fabrication of Small Horizontal axis wind Turbine Rotors at Low Reynolds Number

This research paper presents a design and fabrication of 100 Watt small horizontal axis wind turbine with 0.24 m and 0.35 m rotor radius and tip speed ratio varies from 2 to 10 was designed and development for operated at low wind speed with Low Reynolds number. In this paper, a new airfoil profile was designed and developed, it’s denoted by MK115. The numerical and experimental analysis for 6 airfoils using Xfoil software was conducted with a view to evaluating the lift-to-drag ratio and angle of attack by means of the SD7024, SG6043, NACA2412, S1210, E213, and New Airfoil (MK115) tested. In simulation, new MK115 airfoil was the most convenient airfoil to start high energy production for low-wind applications, on the Reynolds number 25000, 50000, 75000, and 100000 in improved airfoil (MK115) tests an Open type wind tunnel. An Xfoil analysis to obtain further data on the flow characteristics was also conducted. (MK115) airfoil have CLmax of 0.92, 1.25, 1.69, 1.67 at Re=25k, 50k, 75k and 100k for an angle of attack is equal to 100 .A maximum lift to drag ratio (Cl/Cd) of 7,16,50,63 at Re=25k, 50k, 75k and 100k for New airfoil (MK115) at angle of attack (α) =40 , 40 , 80 , 80 . SG6043, NACA2412, E214, SD7034, S1210 and MK115 (New airfoil) have the Maximum Cp=0.37, 0.36, 0.4, 0.39, 0.44, and 0.44 at tip speed ratio (λ) =6 for Reynolds number is equal to 100000. MK115, Maximum Torque obtained 0.9744 Nm, 1.389 Nm and 2.4866 Nm at blade angle =0, 15 and 30 degrees respectively. Power coefficient (Cp) =0.51, 0.5, 0.46, and 0.4 at Rotor shaft angle=00 , 50 , 100 , and 150 respectively for the new airfoil results.

Author(s):  
Manoj Kumar Chaudhary ◽  
◽  
S. Prakash ◽  

In this study, small horizontal-axis wind turbine blades operating at low wind speeds were optimized. An optimized blade design method based on blade element momentum (BEM) theory was used. The rotor radius of 0.2 m, 0.4 m and 0.6 m and blade geometry with single (W1 & W2) and multistage rotor (W3) was examined. MATLAB and XFoil programs were used to implement to BEM theory and devise a six novel airfoil (NAF-Series) suitable for application of small horizontal axis wind turbines at low Reynolds number. The experimental blades were developed using the 3D printing additive manufacturing technique. The new airfoils such as NAF3929, NAF4420, NAF4423, NAF4923, NAF4924, and NAF5024 were investigated using XFoil software at Reynolds numbers of 100,000. The investigation range included tip speed ratios from 3 to 10 and angle of attacks from 2° to 20°. These parameters were varied in MATLAB and XFoil software for optimization and investigation of the power coefficient, lift coefficient, drag coefficient and lift-to-drag ratio. The cut-in wind velocity of the single and multistage rotors was approximately 2.5 & 3 m/s respectively. The optimized tip speed ratio, axial displacement and angle of attack were 5.5, 0.08m & 6° respectively. The proposed NAF-Series airfoil blades exhibited higher aerodynamic performances and maximum output power than those with the base SG6043 and NACA4415 airfoil at low Reynolds number.


2014 ◽  
Vol 1070-1072 ◽  
pp. 1869-1873
Author(s):  
Hai Bo Jiang ◽  
Yun Peng Zhao ◽  
Zhong Qing Cheng

The lift coefficient of any wind turbine must have highest limit. In this paper, an analytical expression of lift coefficient associated with tip-speed ratio and lift-drag ratio of airfoil of wind turbine with ideal chord has been deduced by integrating along the blade wingspan using the blade element - momentum theory, which can be used for pre-estimating lift coefficient of actual wind turbine in design. Further, considering ideal fluid environment ( the drag coefficient is close to 0 ), an expression of the highest performance of lift only associated with tip-speed ratio has been deduced too, which is the highest boundary of lift coefficient of any actual wind turbine with same tip-speed ratio. The results show that for the wind turbine in steady state, there is a theoretical limit of the lift coefficient, 0.57795, which is the highest boundary that any actual wind turbine can not be crossed; if the tip-speed ratio is greater than 6 and lift-drag ratio less than 200, the lift coefficient is unlikely to exceed 0.2.


2002 ◽  
Vol 26 (2) ◽  
pp. 109-116
Author(s):  
Sadhan Mahapatra ◽  
Subhasis Neogi

This paper is based on the studies made on a numerical model for calculating the turbine characteristics at low tip speed ratio for a Horizontal Axis Wind Turbine. The turbine characteristics are analysed for different configurations over the total operating range i.e. from tip speed ratio of zero to a maximum value where CP becomes zero. The simulation model provides acceptable results, however for the blade position near the hub, a non-convergent situation is observed i.e. the flow parameters converge to values outside those associated with turbine operation. This indicates the possibility of a multisolution.


2013 ◽  
Vol 860-863 ◽  
pp. 256-261
Author(s):  
Qiu Hua Chen ◽  
Xu Lai ◽  
Jin Zou

The present paper evaluates the tip vortex evolution of a horizontal axis wind turbine model using the stereo particle image velocimetry technology. The measurements of the wake region up to 2.7 diameters downstream are first conducted using the phase locked technique based on two high speed CCD cameras. Parameters that describe the helical vortex wake, such as the velocity, helicoidal pitch and vortex vorticity, are presented at two tip speed ratios. The vortex interaction and stability of helical vortex filaments within wind turbine wake are seen throughout the measurement domain. The results show the wake structure varies with tip speed ratio, and the helicoidal pitch of tip vortex trajectory reduces while the diffusion of tip vortex is faster with increasing tip speed ratio.


2021 ◽  
pp. 1-28
Author(s):  
Mehmet Numan Kaya ◽  
Faruk Köse ◽  
Oguz Uzol ◽  
Derek Ingham ◽  
Lin Ma ◽  
...  

Abstract The aerodynamic shapes of the blades are still of high importance and various aerodynamic designs have been developed in order to increase the amount of energy production. In this study, a swept horizontal axis wind turbine blade has been optimized to increase the aerodynamic efficiency using the Computational Fluid Dynamics method. To illustrate the technique, a wind turbine with a rotor diameter of 0.94 m has been used as the baseline turbine and the most appropriate swept blade design parameters, namely the sweep start up section, tip displacement and mode of the sweep have been investigated to obtain the maximum power coefficient at the design tip speed ratio. At this stage, a new equation that allows all three swept blade design parameters to be changed independently has been used to design swept blades, and the response surface method has been used to find out the optimum swept blade parameters. According to the results obtained, a significant increase of 4.28% in the power coefficient was achieved at the design tip speed ratio with the new designed optimum swept wind turbine blade. Finally, baseline and optimum swept blades have been compared in terms of power coefficients at different tip speed ratios, force distributions, pressure distributions and tip vortices.


2021 ◽  
Vol 294 ◽  
pp. 01003
Author(s):  
Somaya Younoussi ◽  
Abdeslem Ettaouil

In this paper, an optimization approach of a small horizontal axis wind turbine based on BEM theory including De Vries and Shen et al. tip loss corrections is proposed. The optimal blade geometry was obtained by maximizing the power coefficient along the blade using the optimal angle of attack and the optimal tip speed ratio. The Newton’s iterative method applied to axial induction factor was used to solve the problem. This study was conducted for a NACA4418 small wind turbine, at low wind velocity. Among the two used tip loss corrections, the De Vries correction was found to be the most suitable for this blade optimization method. The optimal design was obtained for a tip speed ratio of 5 and has recorded a power coefficient equal to 0.463.


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