Assessment of the Influence of Tip Speed Ratio, Solidity and Reynolds Number on the Aerodynamic Performance of Selected Locally Fabricated Wind Turbines in Tanzania
Loading...
Date
2019
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The University Of Dar Es Salaam
Abstract
The sites with good wind energy conditions in Tanzania have motivated some local craftsmen to manufacture wind turbines using local and imported materials. However, some studies have shown that these turbines have low performance. In this study, theoretical approach has been carried out to assess the influence of TSR, solidity and Re on the aerodynamic performance of nine selected locally fabricated wind turbines in Tanzania. Three manufacturing centers namely, Dar es Salaam, Singida and Makambako were selected and three different HAWT rotor blades from each center were put under testing. Their respective rotor radii and chord widths were measured and used to determine their TSR, solidity and Re. The measured TSRs were 0.63, 0.70, 0.79, 0.90, 1.57, 2.09, 2.51, 3.14, and 4.19. Unlike 4.19, the rest values were below the recommended range between 4 and 10 for which WECS are recommended to generate large scale electricity. The respective measured solidities were, 0.90, 0.10, 0.13, 0.17, 0.18, 0.28, 0.88, 1.07 and 1.22. These solidities were found to be above the proposed range between 0.01 and 0.05 for which WECS are designed to generate large scale electricity. These high solidities lead into high torques reducing rotational speed of the WECS. The measured Res were 86,030, 99,265, 100,589, 102,574, 125,736, 138,972, 145,589, 145,589 and 152,207. These Re values are below the standard Re which is at least 6 110 implying that they exhibit turbulent flow with high level of drag coefficient that influences low performance of the WECS. The 3 - bladed wind turbine from Matiya in Singida was found to have good TSR of 4.19 though its solidity was found to be above the recommended standard values range. It needs an optimization of its chord and radius to improve its efficiency. Therefore, these wind turbines can only generate small scale electricity due to their poor aerodynamic performances
Description
This thesis was published in the year 2019