Horizontal Axis Wind Turbine Blade Design Methodologies for Efficiency Enhancement—A Review

Abstract

Among renewable sources of energy, wind is the most widely used resource due to its commercial acceptance, low cost and ease of operation and maintenance, relatively much less time for its realization from concept till operation, creation of new jobs, and least adverse effect on the environment. The fast technological development in the wind industry and availability of multi megawatt sized horizontal axis wind turbines has further led the promotion of wind power utilization globally. It is a well-known fact that the wind speed increases with height and hence the energy output. However, one cannot go above a certain height due to structural and other issues. Hence other attempts need to be made to increase the efficiency of the wind turbines, maintaining the hub heights to acceptable and controllable limits. The efficiency of the wind turbines or the energy output can be increased by reducing the cut-in-speed and/or the rated-speed by modifying and redesigning the blades. The problem is tackled by identifying the optimization parameters such as annual energy yield, power coefficient, energy cost, blade mass, and blade design constraints such as physical, geometric, and aerodynamic. The present paper provides an overview of the commonly used models, techniques, tools and experimental approaches applied to increase the efficiency of the wind turbines. In the present review work, particular emphasis is made on approaches used to design wind turbine blades both experimental and numerical, methodologies used to study the performance of wind turbines both experimentally and analytically, active and passive techniques used to enhance the power output from wind turbines, reduction in cut-in-speed for improved wind turbine performance, and lastly the research and development work related to new and efficient materials for the wind turbines.

Development of High Performance Airfoils for Application in Small Wind Turbine Power Generation

“…For small wind turbine applications, low wind speeds are generally characterized by airflows with Reynolds numbers (Re) below 500,000. Under this low Re condition, improperly designed blade airfoils encounter deterioration in aerodynamic performance which adversely affects the operating efficiency of the wind turbine [18][19][20][21]. As such, airfoils designed for large-scale wind turbines are not necessarily suitable for small-scale wind turbines [19,20,22,23].…”

On the design of propeller hydrokinetic turbines: the effect of the number of blades

“…The hydrodynamical design methods for horizontal axis free flow hydrokinetic turbines are similar to those employed in wind turbines or to the propulsion propeller turbomachines. The design approaches can be adapted for the specific situations of hydrokinetic turbines, inheriting the important scientific rationale of the blade design of wind turbines [5,6].…”

Feasibility of a 100 MW Installed Capacity Wind Farm for Different Climatic Conditions

“…These studies include the estimation of wind energy trends using different techniques [15], wind farm layout design optimization [16], analysis of wind power distribution and estimation across different regions [17]. Other studies include the time-dependent estimation of wind speed [18].…”