Fatigue Analysis for Fe-34.5Mn-l0Al-0.76C Tidal Turbine Blades using Rainflow Algorithm

¹College of Technological Studies, Public Authority for Applied Education and Training, Kuwait

²Mechanical Engineering Department, Faculty of Engineering, Alexandria University, Kuwait
³Black Drop Energy Solution (OPC) Pvt. Ltd., Heriot Watt University, Kuwait

Adv. Mater. Lett., 2021, 12 (2), 21021604

DOI: 10.5185/amlett.2021.021604

Publication Date (Web): Dec 16, 2020

Copyright © IAAM-VBRI Press

E-mail: ea.meshaieie@paet edu.kw; eng.ibrahim.elgarhi@gmail.com; blackdropenergy@gmail.com

Abstract

This study investigates the effect of the environmental conditions (seawater mean thrust force and flow velocity) on a tidal turbine for different thicknesses mathematically. This had been achieved through predicting the fatigue stresses applied on the turbine for different conditions using Rainflow algorithm. The blades of the tidal turbine should be characterized by a low roughness to reduce eddies formation downstream the seawater flow. Fe-34.5Mn-l0Al-0.76C alloy had been selected in this study. Obtained results showed that, increasing thickness of the blade resulted in increasing the turbine lifespan for each studied flow velocity and thrust forces. However, increasing the flow velocity is predicted to increase the thrust forces due to the wake region formed downstream the flow leading to increase the fatigue stress on the blade. Consequently, the blade thickness should be optimized based on the geographical location decided to be installed by a turbine. As the geographical location effects on the environmental conditions significantly, which should be considered during the design stage to prevent fatigue failure of the turbine. Optimizing the blade thickness would help in maximizing the energy conversion efficiency of the turbine as well, as a lightweight blade would be able of generating electricity higher than heavy ones.

Keywords

Tidal turbine, Fe-34.5Mn-l0Al-0.76C, blades, rainflow algorithm, fatigue stress, MATLAB.