Vibration Analysis of an Ocean Current Turbine Blade

Abstract

Vibration characteristics of an ocean current turbine blade have been analyzed using Design foil, BET tool, Pro/Engineer and Finite Element Package ANSYS.Natural frequencies and mode shapes of a turbine blade can be evaluated by Vibration Analysis.It can also serve as a starting base for another, dynamic analysis, such as a transient dynamic analysis, or a spectrum analysis.The natural frequencies and mode shapes are important parameter in the design and analysis of an ocean current turbine blade.Modal analysis can also be performed on a pre-stressed spinning turbine blade.It has been investigated that the blade would not fail in an ocean current of 2.3 to 2.5 m/s that can produce power production up to 151 KW.The blade is of Composite structure with carbon fibers and foam core.It is also facilitated with two webs of carbon fibers to add shear rigidity.Eight design cases of blade were analyzed involving the differences in geometry, material properties and internal structures.Results from the vibration analysis revealed that the recommended blade design have adequate frequency difference than the frequency of other components of turbine like rotor, assembly to produce proposed power of 151 KW without any resonance or structural failure.Deflection analysis and Principal stress analysis have been conducted that showed the proposed blade design have adequate strength.