In this paper, along with the progress of modern wind energy technology, the trends of wind energy technology and potential challenges have been studied thoroughly. It is estimated that within the next 2–3 decades, the Vertical Axis Wind Turbine (VAWT) can dominate the wind-energy technology. The VAWT requires less land space and using the same space; it is capable of producing more wind energy than that of its counterpart. By implying the Fish Schooling Concept effectively and successfully, it is possible to advance the wind-energy technology more. In the last 3–4 decades, the wind turbine capacity has been increased around 30–40 times. With the increase of wind energy capacity, the demand of the energy storage system has been increased significantly. Along with the many energy storage systems, fuel cells and batteries are the two most promising devices to meet the demand in RE systems. The wind-energy technology is established itself but not yet fully mature and hence there are many areas where improvements are required to reduce the cost of wind energy.

http://iran-tarjome.persiangig.com/other/1-s2.0-S1364032113000312-main.pdf

Progress and recent trends of wind energy technology

The study of rotor blade aerodynamic performances of wind turbine has been presented in this thesis. This study was focused on aerodynamic effects changed by blade surface distribution as well as grid solution along the airfoil. The details of numerical calculation from Fluent were described to help predict accurate blade performance for comparison and discussion with available data. The direct surface curvature distribution blade design method for two-dimensional airfoil sections for wind turbine rotors have been discussed with the attentions to Euler equation, velocity diagram and the factors which affect wind turbine performance and applied to design a blade geometry close to an existing wind turbine blade, Eppler387, in order to argue that the blade surface drawn by direct surface curvature distribution blade design method contributes aerodynamic efficiency. The FLUENT calculation of NACA63-215V showed that the aerodynamic characteristics agreed well with the available experimental data at lower angles of attack although it was discontinuities in the surface curvature distributions between 0.7 and 0.8 in x/c. The discontinuities were so small that the blade performance could not be affected. The design of Eppler 387 blade performed to reduce drag force. The discontinuities of surface distribution matched the curve of the pressure coefficients. It was found in the curvature distribution that the leading edge pressure side had difficulties to connect to Bezier curve and also the trailing edge circle was never be tangent to the lines of trailing edge pressure and suction sides due to programming difficulties.

Aerodynamics of wind turbines

Blockage corrections in wind tunnel tests of small horizontal-axis wind turbines

Wind energy continues to stand out as a more established and mature technology to offset a large proportion of power. Efforts aimed at improving wind energy use to meet the energy demand in turbulent urban wind environment have been the main technical focus. In previous studies on wind resource and behavior in urban environment, different designs of horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) have been reviewed. This paper vividly captures the fact that wind resource has a great potential to be fully explored and developed in the urban environment. Varying ways of application and application techniques being applied for electrical generation, ventilation and pollution dispersion, onshore cooling and dehumidification of coastal urban cities, and economics and environmental benefits of applying wind energy in urban environments are summarized. Although many new ideas and solutions that factor technical, economical and environmental sustainability in urban areas are coming up every day, challenges in design are gradually being solved to take advantage of urban low and turbulent wind speed characteristics, installation space challenges, vibration and noise reduction, among others. Some of the unique solutions that have been and are being developed in the applications of wind energy technology in urban environments are also reported in this paper.

Advances in wind energy resource exploitation in urban environment: A review

Urban wind conditions and small wind turbines in the built environment: A review

Experimental study of wind-turbine airfoil aerodynamics in high turbulence

Rotational and turbulence effects on a wind turbine blade. Investigation of the stall mechanisms

Incident flows on wind turbines are often highly turbulent, because these devices operate in the atmospheric boundary layer and often in the wake of other wind turbines This article presents experimental investigations of the effects of a high turbulence level on wind turbine aerodynamics Power and thrust are measured on a horizontal axis wind turbine model in the ‘Lucien Malavard’ wind tunnel A grid is used to generate three turbulence levels (4·4%, 9% and 12%) with integral length scale of the order of magnitude of the chord length Experiments show little effect of turbulence on the wind turbine model power and thrust This can be justified by analysis of the aerodynamic loads along the blade Copyright © 2005 John Wiley & Sons, Ltd

Experimental study of the effect of turbulence on horizontal axis wind turbine aerodynamics

Steady two-dimensional free-surface flows of an inviscid incompressible fluid are studied here, using the complex potential theory. The first flow is a uniform free stream flow in a channel of finite depth. The second is similar, but terminated abruptly as a downstream flow exiting into a falling jet, with and without the effect of gravity. These problems have already been solved for polygonal walls. This paper presents an iterative process for computing flows over arbitrarily shaped channels, with and without the presence of a waterfall at the exit. This process is based on the solution of a mixed boundary problem in the unit disk. The method emphasizes the correspondence between the walls in the physical plane and in the unit disk. The numerical data agree with previously published results and extend them to arbitrary curved walls. This method yields solutions only for supercritical flows.

Open-channel flows and waterfalls

We consider the two-dimensional potential flow of a liquid issuing from a nozzle, for which the far upstream flow tends to be uniform and horizontal. The problem is solved by mapping the potential plane ( f ) onto a unit disk and then solving a mixed boundary problem. Using an iterative process, we can consider either polygonal walls or arbitrary curved walls. By considering polygonal walls, our method is first validated by comparison with results already published for weightless fluid. It is next applied to arbitrary curved walls, with or without gravity.

Jacques Hureau

Papers

Experimental study of wind-turbine airfoil aerodynamics in high turbulence

Rotational and turbulence effects on a wind turbine blade. Investigation of the stall mechanisms

Experimental study of the effect of turbulence on horizontal axis wind turbine aerodynamics

Open-channel flows and waterfalls

Potential flow issuing from a two-dimensional curved nozzle