Wind turbines reliability is affected by stochastic factors in the turbulent inflow and wind turbine structures. On one hand, the variability in wind dynamics and the inherent stochastic structures result in random loads on wind turbine rotor and tower. On the other hand, the inherent structural uncertainties caused by imperfect control of manufacturing process introduce unpredictable failures ...

Abstract: Wind turbine blades have to withstand the rigorous test of 20–25 years of service. Fatigue testing is an accurate method used to verify blade reliability. Multi-point excitation could better fit the fatigue damage distribution, which reduces the power output of a single exciter and saves testing energy consumption. The amplitude, phase, and frequency characteristics of the fatigue tes...

This paper presents the SHM result of a 9m CX-100 wind turbine blade under fullscale fatigue loads. The test was performed at the National Renewable Energy Laboratory. The 9-meter blade was instrumented with piezoelectric transducers, accelerometers, acoustic emission sensors, and foil strain gauges on the surface of the blade. The blade underwent fatigue excitation at 1.8 Hz for defined interv...

High-pressure turbine blades in a gas turbine engine are constantly exposed to extremely hostile operating conditions, where temperatures can regularly exceed the melting point of the parent material. These conditions make the blades susceptible to thermal fatigue cracking, corrosion and, in some cases, damage due to particle impact. The required inspection method in aerospace for finding surfa...

An experimental investigation of the local film cooling effectiveness and heat transfer coefficient downstream of a row of elongated holes in a simulated axial turbine blade tip is presented. Film cooling is needed to protect the turbine blade tip region from high heat transfer rates, especially when cooling by convection is insufficient to keep the temperature distribution of the blade within ...

High cycle fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Single crystal nickel turbine blades are being utilized in rocket engine turbopumps and jet engines throughout industry because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the m...

A disturbance accommodating controller (DAC) to reject wind speed perturbations is applied on a 5MW wind turbine mounted on a tension leg platform (TLP). Multi-blade coordinate (MBC) transformation is used to address the periodicity of the floating wind turbine system. A method to apply DAC after applying MBC transformation is developed and several implementation options are presented. Simulati...

In non-destructive testing (NDT) it is important to have a high probability of detection (POD) and reliable characterization of each defect. This can be gained by using several techniques, which leads to an increase in cost and time for testing. Another option is to use several techniques combined into a single probe, in which case data fusion for the techniques is possible. A dual probe contai...

In order to explore measuring accuracy of coded-structured-light 3D measurement system onto high reflectance surface of turbine blade, measuring error analysis, system parameter design and uncertainty evaluation were investigated. First, device parameters and azimuth parameters of analytic geometry model and projective geometry model of coded structured light system were analyzed and unified. S...

wind power has been widely considered in recent years as an available and a clean renewable energy source. the cost of wind energy production is currently the main issue, and increasing the size of wind turbines can reduce wind energy production costs. hence, megawatt wind turbines are being rapidly developed in recent years. in this paper, an aerodynamic analysis of the nrel 5mw turbine is car...