Recent Development in the Design of Wind Deflectors for Vertical Axis Wind Turbine: A Review

Altaf Hussain Rajpar,Ahmad E Eladwi,Mohamed Bashir Ali Bashir,Imran Ali

doi:10.3390/en14165140

Abstract

Developments in the design of wind turbines with augmentation are advancing around the globe with the goal of generating electricity close to the user in built-up areas. This is certain to help lessen the power generation load as well as distribution and transmission network costs by reducing the distance between the user and the power source. The main objectives driving the development and advancement of vertical-axis wind turbines are increasing the power coefficient and the torque coefficient by optimizing the upstream wind striking on the rotor blades. Unlike horizontal-axis wind turbines, vertical axis turbines generate not only positive torque but also negative torque during operation. The negative torque generated by the returning blade is a key issue for vertical-axis wind turbines (VAWTs) that is counterproductive. Installation of wind deflectors for flow augmentation helps to reduce the negative torque generated by the returning blades as well as enhance the positive torque by creating a diversion in the upstream wind towards the forwarding blade during operation. This paper reviews various designs, experiments, and CFD simulations of wind deflectors reported to date. Optimization techniques for VAWTs incorporating wind deflectors are discussed in detail. The main focus of the review was on the installation position and orientation of the deflectors and their potential contribution to increasing the power coefficient. Topics for future study are suggested in the conclusion section of the paper.

Highlights

Increasing concerns about environmental pollution and degradation, climate change, global warming, and sustainable socio-economic development are among the reasons for the advancement and development of renewable energy systems [1,2]
One of the methods to improve the performance (Cp value) and self- starting ability is flow augmentation, where the wind turbine design is optimized in a way that the upstream wind is appropriately blocked while ensuring maximum positive torque and minimum negative torque achieved [31]
vertical-axis wind turbines (VAWTs) are best known for working under variable wind speeds and easy installation; on the downside, poor self-starting performance, low initial torque, and lower power coefficients are their main disadvantages

Summary

Introduction

Increasing concerns about environmental pollution and degradation, climate change, global warming, and sustainable socio-economic development are among the reasons for the advancement and development of renewable energy systems [1,2]. Renewable energy demand is likely to increase four- to five-fold with population growth, as predicted in the World Energy Council (WEC) Scenarios to the year 2050. Renewable energy generation will continue its expansion in the future energy mix of the year 2050, as predictions indicate it will show the highest growth rate among other sources [3]. Wind energy is the most promising source amongst all renewable energy sources and is considered as a major investment sector by WEC to meet future electricity demand [3]. To ensure compatibility between the targeted goal and wind energy development, the availability of databases on energy exploration, generation and consumption are important. The statistical analysis of these databases helps policymakers to assess the feasibility of renewable energy generation targets for the year 2050 and engage in relevant planning [4]

Objectives

Methods

Findings

Discussion

Conclusion