Influence of blade length on kinematic feature of cylinder blade wind turbine driven by longitudinal vortex

2018 ◽  
Vol 2018 (0) ◽  
pp. OS6-2
Author(s):  
Kasumi SAKAMOTO ◽  
Withun HEMSUWAN ◽  
Tsutomu TAKAHASHI
Author(s):  
Fouad Mohammad ◽  
Emmanuel Ayorinde

The aerodynamic loadings that act on the blade of a horizontal axis wind turbine change as a function of time due to the instantaneous change of the wind speed, the wind direction and the blade position. The new contribution in this study is the introduction of a simplified non CFD based procedure for the calculation of all the aerodynamic loadings acting on a wind turbine blade. The premise of the current simplified model is that (a) the forces can be modeled by a set of point loads rather than distributed pressures, and (b) the magnitudes of these point loads can be estimated using the below load formulas, (c) an interpolation scheme needed to have all computed forces and moments as a function of the blade lengthwise x. Considering a 14m blade length and utilizing a time dependent set of parameters such as angle of attack, material and air density, wind and blade speed, flow angle, yaw, pitch angles, the centrifugal forces (along x-direction of the blade length), the cross-sectional forces (Fy and Fz) and the twisting moment of the blade (about the x-direction) were calculated for each of all the given time steps. After that the authors explain how to interpolate the calculated loadings (forces and twisting moment) and the right formulas to compute the aerodynamic load vector (the right side of the dynamic equations of motion).


2018 ◽  
Vol 8 (9) ◽  
pp. 1668 ◽  
Author(s):  
Jianghai Wu ◽  
Tongguang Wang ◽  
Long Wang ◽  
Ning Zhao

This article presents a framework to integrate and optimize the design of large-scale wind turbines. Annual energy production, load analysis, the structural design of components and the wind farm operation model are coupled to perform a system-level nonlinear optimization. As well as the commonly used design objective levelized cost of energy (LCoE), key metrics of engineering economics such as net present value (NPV), internal rate of return (IRR) and the discounted payback time (DPT) are calculated and used as design objectives, respectively. The results show that IRR and DPT have the same effect as LCoE since they all lead to minimization of the ratio of the capital expenditure to the energy production. Meanwhile, the optimization for NPV tends to maximize the margin between incomes and costs. These two types of economic metrics provide the minimal blade length and maximal blade length of an optimal blade for a target wind turbine at a given wind farm. The turbine properties with respect to the blade length and tower height are also examined. The blade obtained with economic optimization objectives has a much larger relative thickness and smaller chord distributions than that obtained for high aerodynamic performance design. Furthermore, the use of cost control objectives in optimization is crucial in improving the economic efficiency of wind turbines and sacrificing some aerodynamic performance can bring significant reductions in design loads and turbine costs.


Author(s):  
Vasishta Bhargava ◽  
Rahul Samala

Research on broadband aerodynamic noise from wind turbine blades is becoming important in several countries. In this work, computer simulation of acoustic emissions from wind turbine blades are predicted using quasi empirical model for a three-bladed horizontal axis 3 MW turbine with blade length ~47 m. Sound power levels are investigated for source and receiver height of 80 m and 2 m above ground and located at a distance equal to total turbine height. The results are validated using existing experimental data for Siemens SWT-2.3 MW turbine having blade length of 47 m, as well as with 2.5 MW turbine. Aerofoil self-noise mechanisms are discussed in present work and results are demonstrated for wind speed of 8 m/s. Overall sound power levels for 3 MW turbine showed good agreements with the existing experiment data obtained for SWT-2.3 MW turbine. Noise map of single source sound power level, dBA of an isolated blade segment located at 75 %R for single blade is illustrated for wind speed of 8 m/s. The results demonstrated that most of the noise production occurred from outboard section of blade and for blade azimuth positions between 80° and 170°.


2021 ◽  
Vol 87 (894) ◽  
pp. 20-00365-20-00365 ◽  
Author(s):  
Kasumi SAKAMOTO ◽  
Keita UDAKA ◽  
Withun HEMSUWAN ◽  
Tsutomu TAKAHASHI

2015 ◽  
Vol 793 ◽  
pp. 333-337 ◽  
Author(s):  
Abadal Salam T. Hussain ◽  
S. Faiz Ahmed ◽  
F. Malek ◽  
M.S. Jawad ◽  
Nursabrina Noorpi ◽  
...  

In many countries fossil fuels are used as the main source to generate electricity, but due to the increase in energy consumption and the rapid depletion of the fossil fuel resources, the demand of alternate energy sources such as solar, wind or hydro power becomes high [1]. In this paper wind energy as an alternate energy resource for electric power generation is proposed in the form of a small wind farm for grid-connected application in Perlis Malaysia. The monthly wind speed data of Perlis which is the smallest state of Malaysia were measured and the wind mill parameters such as Air Density, Blade Length, Power Coefficient and Blade Length were calculated. The mechanical output power of the proposed wind turbine form is calculated to check out its performance and reliability. The results showed that the proposed wind energy power generating system is a good choice and can be implemented in Malaysia to provide enough power for small towns and rural areas.


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