scholarly journals A Robot-Assisted Large-Scale Inspection of Wind Turbine Blades in Manufacturing Using an Autonomous Mobile Manipulator

2021 ◽  
Vol 11 (19) ◽  
pp. 9271
Author(s):  
Heiko Engemann ◽  
Patrick Cönen ◽  
Harshal Dawar ◽  
Shengzhi Du ◽  
Stephan Kallweit
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Large Scale ◽  
Turbine Blades ◽  
Rotor Blades ◽  
Mobile Manipulator ◽  
Wind Turbine Blades ◽  
Left Hand ◽  
Planning Strategy ◽  
Execution Strategy

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.

scholarly journals Forgószárnyas repülőgép rotorok aeroelasztikus viselkedésének vizsgálata szélturbina lapátok számára kifejelsztett eszközökkel

2019 ◽  
Vol 31 (2) ◽  
pp. 115-126
Author(s):  
Balázs Gáti ◽  
Tamás Gausz
Keyword(s):  
Wind Turbine ◽  
Software Package ◽  
Rotor Blade ◽  
Numerical Solutions ◽  
Turbine Blades ◽  
Rotor Blades ◽  
Wind Turbine Blades ◽  
Operational Conditions ◽  
Rotary Wing ◽  
Multiple Analysis

Rotor blades of an autorotating helicopter or a gyrocopter work very similar to the rotor blades of a wind turbine in skew wind. In this publication we present the result of multiple analysis of a rotor blade of a rotary-wing airplane, but the analyses were performed with a software package developed for investigation of wind turbine blades. The results of several analyses seem to be valid for rotary-wing airplanes in some special, but very important cases, and can be useful for more detailed investigation. It was stated, that the fact leads to uninterpretable numerical solutions, that the angle between the undisturbed airflow and the Tip Path Plane is much lower in case of helicopters and gyrocopters than by wind turbines in most operational conditions .

scholarly journals Automated Detection of Premature Flow Transitions on Wind Turbine Blades Using Model-Based Algorithms

2021 ◽  
Vol 11 (18) ◽  
pp. 8700
Author(s):  
Ann-Marie Parrey ◽  
Daniel Gleichauf ◽  
Michael Sorg ◽  
Andreas Fischer
Keyword(s):  
Turbulent Flow ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Rotor Blade ◽  
Turbine Blades ◽  
Rotor Blades ◽  
Wind Turbine Blades ◽  
Model Based ◽  
Negative Effect ◽  
Layer Flow

Defects on rotor blade leading edges of wind turbines can lead to premature laminar–turbulent transitions, whereby the turbulent boundary layer flow forms turbulence wedges. The increased area of turbulent flow around the blade is of interest here, as it can have a negative effect on the energy production of the wind turbine. Infrared thermography is an established method to visualize the transition from laminar to turbulent flow, but the contrast-to-noise ratio (CNR) of the turbulence wedges is often too low to allow a reliable wedge detection with the existing image processing techniques. To facilitate a reliable detection, a model-based algorithm is presented that uses prior knowledge about the wedge-like shape of the premature flow transition. A verification of the algorithm with simulated thermograms and a validation with measured thermograms of a rotor blade from an operating wind turbine are performed. As a result, the proposed algorithm is able to detect turbulence wedges and to determine their area down to a CNR of 2. For turbulence wedges in a recorded thermogram on a wind turbine with CNR as low as 0.2, at least 80% of the area of the turbulence wedges is detected. Thus, the model-based algorithm is proven to be a powerful tool for the detection of turbulence wedges in thermograms of rotor blades of in-service wind turbines and for determining the resulting areas of the additional turbulent flow regions with a low measurement error.

scholarly journals Damage tolerance and structural monitoring for wind turbine blades

2015 ◽  
Vol 373 (2035) ◽  
pp. 20140077 ◽  
Author(s):  
M. McGugan ◽  
G. Pereira ◽  
B. F. Sørensen ◽  
H. Toftegaard ◽  
K. Branner
Keyword(s):  
Wind Turbine ◽  
Damage Tolerance ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Offshore Wind ◽  
Tolerance Index ◽  
Wind Turbine Blades ◽  
Efficient Operation ◽  
Reliable Design

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques and modelling to manage the life cycle of the structures. This will allow an efficient operation of the wind turbine in terms of load alleviation, limited maintenance and repair leading to a more effective exploitation of offshore wind.

Parametric Stiffness in Large-Scale Wind-Turbine Blades and the Effects on Resonance and Speed Locking

2020 ◽  
Author(s):  
Ayse Sapmaz ◽  
Brian F. Feeny
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Turbine Blades ◽  
Relative Strength ◽  
Wind Turbine Blades ◽  
Fixed Position ◽  
Horizontal Axis Wind Turbine ◽  
Parametric Effect ◽  
Parametric Effects ◽  
Blade Tip

Abstract This paper is on parametric effect in large scale horizontal-axis wind-turbine blades and speed locking phenomenon for a simplified model of the in-plane blade-hub dynamics. The relative strength of the parametric stiffness is evaluated for actual and scaled-length blades. Fixed-position natural frequencies are found at different rotation angles to show the significance of the gravity’s parametric effect. The ratio of the parametric and elastic modal stiffness is then estimated for the scaled versions of the NREL’s blades for four models to present the relation between the blade size and the parametric effects. The parametric effect on blade tip placements are investigated for superharmonic resonances at orders two and three for blades of various lengths. An analysis of speed-locking is presented, and interpreted for the various blades.

Nonlinear Dynamics of a Rotary Energy Harvester With a Double Frequency Up-Conversion Mechanism

2020 ◽  
Vol 15 (9) ◽  
Author(s):  
Saman Nezami ◽  
Soobum Lee
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Energy Harvester ◽  
Turbine Blades ◽  
Physical Contact ◽  
Wind Turbine Blades ◽  
Double Frequency ◽  
Coupled Equations ◽  
Piezoelectric Energy ◽  
Cantilevered Beam

Abstract This paper develops a mathematical model of a two degree-of-freedom piezoelectric energy harvester (PEH) in which vibration is driven by disk swing motion. The proposed device converts slow mechanical rotation into piezoelectric vibration using gravity force and magnetic repelling force. The harvester consists of a disk and a piezoelectric cantilevered beam. The disk with an unbalanced mass swings on a rotating object (e.g., wind turbine blade) and two magnets attached to both the beam and the disk can transfer the kinetic energy of the disk to the beam without physical contact. The energy method is used to derive three coupled equations to model the motion of the disk, vibration of the beam, and the piezoelectric voltage output. The effect of harvester orientation on power generation performance is studied as the rotational speed changes, and the simulation results are experimentally verified. Possible application of this energy harvester to a power-sustainable sensor node for large-scale wind turbine blades monitoring is discussed.

scholarly journals Experimental Investigation of Finite Aspect Ratio Cylindrical Bodies for Accelerated Wind Applications

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 25 ◽  
Author(s):  
Michael Parker ◽  
Douglas Bohl
Keyword(s):  
Aspect Ratio ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Cylindrical Body ◽  
Turbine Rotor ◽  
Flow Speed ◽  
The Body ◽  
Rotor Blades ◽  
Wind Turbine Blades ◽  
Smooth Cylinder

The placement of a cylindrical body in a flow alters the velocity and pressure fields resulting in a local increase in the flow speed near the body. This interaction is of interest as wind turbine rotor blades could be placed in the area of increased wind speed to enhance energy harvesting. In this work the aerodynamic performance of two short aspect ratio (AR = 0.93) cylindrical bodies was evaluated for potential use in “accelerated wind” applications. The first cylinder was smooth with a constant diameter. The diameter of the second cylinder varied periodically along the span forming channels, or corrugations, where wind turbine blades could be placed. Experiments were performed for Reynolds numbers ranging from 1 × 105 to 9 × 105. Pressure distributions showed that the smooth cylinder had lower minimum pressure coefficients and delayed separation compared to the corrugated cylinder. Velocity profiles showed that the corrugated cylinder had lower peak speeds, a less uniform profile, and lower kinetic energy flux when compared to the smooth cylinder. It was concluded that the smooth cylinder had significantly better potential performance in accelerated wind applications than the corrugated cylinder.

scholarly journals Wind turbine wake vortex influence on safety of small rotorcraft

2019 ◽  
Vol 123 (1267) ◽  
pp. 1374-1395
Author(s):  
Berend G. van der Wall
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Safety Concern ◽  
Turbine Blades ◽  
Wake Vortex ◽  
Wind Turbine Blades ◽  
Blade Element Theory ◽  
Rotor Disk ◽  
Lifting Surfaces ◽  
Turbine Wake

ABSTRACTThe wake vortex of lifting surfaces such as wind turbine blades or fixed-wing aircraft can heavily affect the blade aerodynamics of rotorcraft. Using blade element theory, the pilot control inputs required to mitigate such vortex effects are estimated and compared to the available control margin at the operating condition of interest. In contrast, when no pilot action is performed, the rotor blade flapping caused by the vortex is evaluated and compared to available margins. It is a safety concern when the remaining margins become zero. The influence of the vortex strength, its core radius and orientation to the rotor disk are evaluated and the effect of rotor blade characteristics (Lock number, natural frequency) is investigated.

Visual Similarity to Aid Alternative-Use Concept Generation for Retired Wind-Turbine Blades

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
E. Kwon ◽  
A. Pehlken ◽  
K.-D. Thoben ◽  
A. Bazylak ◽  
L. H. Shu
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Large Scale ◽  
Turbine Blades ◽  
Visual Similarity ◽  
Concept Generation ◽  
Wind Turbine Blades ◽  
Similar Images ◽  
Disposal Options ◽  
New Framework

The challenge of finding alternative uses for retired wind-turbine blades, which have limited disposal options, motivates this work. Two reuse concept-generation activities (CGAs) conducted in German universities revealed difficulties with the parts' large scale and seeing beyond their original use. Existing methods, e.g., using functional analogy, are less applicable, since for safety reasons, these parts should not be reused to fulfill the same function. Therefore, this work explores the use of visual similarity to support reuse-concept generation. A method was developed that (1) finds visually similar images (VSIs) for wind-turbine-blade photos and (2) derives potential-reuse concepts based on objects that are visually similar to wind-turbine blades in these images. Comparing reuse concepts generated from the two methods, VSI produced fewer smaller-than-scale concepts than CGA. While other qualities such as feasibility depend on the specific photo selected, this work provides a new framework to exploit visual similarity to find alternative uses. As demonstrated for wind-turbine blades, this method aids in generating alternative-use concepts, especially for large-scale objects.

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