scholarly journals Analysis of Modal Parameters Using a Statistical Approach for Condition Monitoring of the Wind Turbine Blade

2020 ◽  
Vol 10 (17) ◽  
pp. 5878 ◽  
Author(s):  
Lukasz Dolinski ◽  
Marek Krawczuk

The primary objective of the presented paper is the numerical and experimental investigation related to developing a useful diagnostic method, which can be used for determining the site and size of damage in laminated shells of wind turbine blades. The described detection technique is based on the analysis of low frequencies bending vibrations mode shapes of rotor blades. The authors used the commonly applied statistics methods that have been adapted to detect edges of damage, including the normalized determination coefficient fit, which is a measure of the absolute fit between two curves. The research was conducted for a scaled-down blade of a three-bladed horizontal-axis wind turbine with 36 m diameter rotor. The study was divided into two parts. The first stage included numerical calculations using the finite element method, which were supplemented in the second stage by measurements under laboratory conditions of the specially manufactured composite blade. The forms of natural vibrations for intact and damaged blade were determined using Laser Doppler Scanning Vibrometry. The results of the presented research confirm the effectiveness of the modal analysis combined with statistic calculation in damage detection. The method points out the location of relatively small damage.

2013 ◽  
Vol 790 ◽  
pp. 655-658
Author(s):  
Chi Chen ◽  
Min Wang ◽  
Long Zou

The modal analysis is an approximate method to study the dynamic characteristics of the structure, the modal is the natural vibration characteristics of the structure, each modal has a specific natural frequency, damping ratios and mode shapes. This thesis will take 1.2MW horizontal axis wind turbine blade for example, and use parametric language APDL of ANSYS for directly modeling, then set the basic parameters of the material, mesh and discuss modal analysis, lastly conduct a detailed analysis of the results.


Author(s):  
Ryoichi S. Amano ◽  
Pradeep Mohan Mohan Das ◽  
Mohammed Alnakhli

This paper presents the comparison of the wake sizes and shapes between two different designs of a horizontal axis wind turbine (HAWT) rotor blades; one a straight edged and the other with a backward sweep. The straight edge blade was constructed so that it is optimal for on coming wind and rotation speeds with 7m/s and 23rpm. The blade has a length of 20m and uses a constant airfoil cross section. The swept edge blade has the same characteristics as the straight edge except for the trajectory of the edge. Each swept blade has the same cross section with the same dimensions at the same distance from the hub as its corresponding section in the straight edge blade. The analysis was done at a range of velocities from 7 m/s to 18 m/s. It was confirmed that the stall region observed by previous studies is in fact due to the flow separation throughout the span of the blade for both the straight and swept blades. A comparison of wake lengths for both straight and swept blades was done for a range of wind velocities. It was shown that the wake length for swept edged blades were longer than for straight blades and both start decreasing beyond the stall region. From a comparison of flow separation angles from experiments and CFD computations, both were observed to follow the same trends at high Reynolds numbers.


2021 ◽  
Vol 11 (19) ◽  
pp. 9271
Author(s):  
Heiko Engemann ◽  
Patrick Cönen ◽  
Harshal Dawar ◽  
Shengzhi Du ◽  
Stephan Kallweit

Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to increase the overall productivity and to create a consistent reliable database for each individual rotor blade. The focus of this paper is set on the process of rotor blade inspection automation by utilizing an autonomous mobile manipulator. The main innovations include a novel path planning strategy for zone-based navigation, which enables an intuitive right-hand or left-hand driving behavior in a shared human–robot workspace. In addition, we introduce a new method for surface orthogonal motion planning in connection with large-scale structures. An overall execution strategy controls the navigation and manipulation processes of the long-running inspection task. The implemented concepts are evaluated in simulation and applied in a real-use case including the tip of a rotor blade form.


Sign in / Sign up

Export Citation Format

Share Document