Non-destructive testing of wind turbines using ultrasonic waves

Abstract

Turbulence influences the amount of wind energy harvested using wind turbine blades reducing the efficiency of the overall electric power production of wind turbines. This results to a lower level of competitiveness of this industry in comparison with other energy sources such as fossil fuel-based power generation. Turbulence effects can be further enhanced by in the characteristics of the wind turbine blade surface itself, for example ice accumulation, impacting insects, dirt, mud. Non-destructive testing (NDT) techniques can be applied in order to monitor the blade surface characteristics or condition. However, NDTs are yet to be widely employed for this particular purpose in the industry yet. This chapter looks into the application of ultrasonic waves for monitoring the presence of dirt, mud, and other potential surface artefacts potentially accumulating with time. Several scenarios have been considered in order to validate this particular approach, considering various levels of mud. Pattern recognition employing neural networks has been considered for the detection and quantification of accumulation of mud on the blade surface.