Wind turbine blades are complicated objects for inspection because they have a curved surface, are multi-layered, have variable thickness and are made from anisotropic materials. Ultrasonic contact pulse-echo immersion testing with moving water container has been selected for inspection of wind turbine blades, because this type of the inspection can be performed having access just from the one ...

This paper is devoted to solve the problem of stall flutter suppression for an absolutely divergent blade of small scale wind turbine. The blade is specially designed with absolutely divergent motions for the purpose of determining the most effective methods of active control for stall flutter suppression. A 2-DOF blade section is considered, with a simplified stall nonlinear aerodynamic model ...

A contra-rotating marine current turbine has a number of attractive features: near-zero reactive torque on the support structure, near-zero swirl in the wake, and high relative interrotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing t...

The control strategies of blade loads are proposed for the characteristics of blade stresses of variable-speed variablepitch wind turbine. Blade loads are divided into two static and dynamic components. The pitch angle and generator torque are controlled by Single neuron PID controller in the static part. Variables are converted from rotational coordinate to fixed coordinate through multi-blade...

ANALYSIS OF WIND TURBINE BLADE VIBRATION AND DRIVETRAIN LOADS By Venkatanarayanan Ramakrishnan The reliability of wind turbines is a major issue for the industry. Drivetrain and blade failures are common, costly and not fully understood. Designers must thus examine and understand the key parameters that influence reliability. As wind turbines increase in size, the blades are designed to be more...

A new composite turbine control architecture that consists of feedforward and feedback parts based on the upwind speed measurements and wind speed measurements at the turbine site, respectively, is described. The algorithm starts with preprocessing of a low-rate sampled upwind speed via the spline interpolation method. A run-ahead model driven by the signals from a preprocessing block models th...

Laser-Doppler velocimetry measurements through a one millimeter hole in the casing of an annular turbine cascade were performed in the endwall region downstream of the blade row. Complementary threehole pressure probe measurements were also taken downstream of the nozzle blades, as well as blade surface pressure measurements. The object of this study was to devise methods for the measurement cl...

The second part of this paper presents results of stress analysis of the whole Francis turbine runner at Derbendikan power station by using the Finite Element Method (FEM). Computations were carried out with appropriate boundary and loading conditions for water pressure obtained from CFD analysis. The analysis focuses on stress distribution in the runner blades. It has been found that the maxim...

The design of a turbine blade cooling system is a multi-objective optimisation problem involving constraints and complex interaction among its design variables. The aim of this paper is to develop a methodology to optimise this design using Evolutionary Computing techniques. This paper presents Generalised Regression Genetic Algorithm (GRGA) and the mathematical model of a real-life turbine bla...

wind power has been widely considered and utilized in recent years as one of the most promising renewable energy sources. in the current research study, aerodynamic analysis of the upwind three-bladed horizontal axis turbine is carried out using blade element momentum theory (bem), and a genetic algorithm (ga) is applied as an optimization method. output power generation is considered as an obj...