CFD-Based Performance Analysis and Experimental Investigation of Design Factors of Vertical Axis Wind Turbines under Low Wind Speed Conditions in Thailand

Suchaya Unsakul,Thananchai Leephakpreeda,Chaianant Sranpat,Pongchalat Chaisiriroj

doi:10.4236/jfcmv.2017.54007

Suchaya Unsakul, Thananchai Leephakpreeda + Show 2 more

Open Access

https://doi.org/10.4236/jfcmv.2017.54007

Copy DOI

Abstract

This paper presents effects of design factors on mechanical performance of Vertical Axis Wind Turbines (VAWTs), and an experimental investigation of optimal VAWT performance under low wind speed conditions in Thailand. Design factors include types of wind turbines, number of blades, types of materials, height-to-radius ratios, and design modifications. Potential VAWT models with different design factors are numerically analyzed within a virtual wind tunnel at various wind speeds by utilizing XflowTM Computational Fluid Dynamics (CFD) software. The performance curves of each VAWT are obtained as plots of power coefficients against tip speed ratios. It is found that the type of wind turbine, number of blades, and height-to-radius ratio have significant effects on mechanical performance whereas types of materials result in shifts of operating speeds of VAWTs. Accordingly, an optimal VAWT prototype is developed to operate under actual low speed wind conditions. The performance curve from experimental results agrees with the CFD results. The proposed methodology can be used in the computer design of VAWTs to improve mechanical performance before physical fabrication.

Highlights

Wind has been an important energy source due to its renewability and sustainability
This paper presents effects of design factors on mechanical performance of Vertical Axis Wind Turbines (VAWTs), and an experimental investigation of optimal VAWT performance under low wind speed conditions in Thailand
Computational Fluid Dynamics (CFD)-based studies of mechanical performances are presented with respect to design factors: material types, number of turbine blades, height to radius ratios, design modification, and turbine patterns

Summary

Introduction

VAWTs have efficiently omnidirectional capability to harvest wind energy at low wind speed conditions. VAWTs with wind boosters are highly suitable under the low wind speed conditions of Thailand [2]. For standalone VAWTs, there were some sustainable developments of Savonius rotors for wind turbines to improve power generation in the past [3] [4] [5] [6]. Different geometries of Savonius VAWT are investigated in order to determine the most effective conditions. D’Alessandro and et al derived mathematical models for determining the mechanical performance of wind turbines [9]. It was reported that the mathematical models led to efficient rotors for VAWTs. Salyers performed experimental investigations of aerodynamic improvement for VAWTs [10]

Methods

Results

Conclusion