scholarly journals Finite Strain Modelling for Multiphase Flow in Dual Scale Porous Media During Resin Infusion Process

2021 ◽  
Vol 127 (1) ◽  
Author(s):  
Ruoyu Huang
Keyword(s):  
Multiphase Flow ◽  
Large Scale ◽  
Finite Strain ◽  
Turbine Blades ◽  
Void Space ◽  
Wind Turbine Blades ◽  
Resin Infusion ◽  
Modelling Framework ◽  
Strain Formulation ◽  
Dual Scale

AbstractResin infusion is a pressure-gradient-driven composite manufacturing process in which the liquid resin is driven to flow through and fill in the void space of a porous composite preform prior to the heat treatment for resin solidification. It usually is a great challenge to design both the infusion system and the infusion process meeting the manufacturing requirements, especially for large-scale components of aircraft and wind turbine blades. Aiming at addressing the key concerns about flow fronts and air bubble entrapment, the present study proposes a modelling framework of the multiphase flow of resin and air in a dual scale porous medium, i.e. a composite preform. A finite strain formulation is discussed for the fluid–solid interaction during an infusion process. The present study bridges the gap between the microscopic observation and the macroscopic modelling by using the averaging method and first principle method, which sheds new light on the high-fidelity finite element modelling.

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.

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.

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.

Dynamic Stall on Rotating Airfoils: A Look at the N-Sequence Data from the NREL Phase VI Experiment

2013 ◽  
Vol 569-570 ◽  
pp. 611-619 ◽  
Author(s):  
Srinivas Guntur ◽  
Niels N. Sørensen ◽  
Scott Schreck
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Sequence Data ◽  
Turbine Blades ◽  
Angle Of Attack ◽  
Dynamic Stall ◽  
Wind Turbine Blades ◽  
Flow Solver ◽  
The Mean ◽  
Nrel Phase Vi

This paper presents an investigation on the combined effect of dynamic stall and rotational augmentation on wind turbine blades. Dynamic stall and rotational augmentation have previously been studied independently. The NREL Phase VI experiment was one large scale experiment that recorded 3D measurements on rotating and pitching airfoils, and using some these data the behaviour of the unsteady CL-α polars under the influence of rotation is investigated. Unsteady DES CFD computations of the Phase VI rotor in axial operation and continuous pitching conditions (reproducing conditions similar to the N-sequence experiments) for select cases have also been carried out using the in-house flow solver EllipSys3D. The resulting set of CL-α curves for the airfoils in rotation operating at various values of the frequency, the mean, and the amplitude of the angle of attack resulting from the CFD computations as well as those from the experiments are presented and discussed. Qualitative differences between dynamic stall occurrence on rotating and stationary airfoils are highlighted, procedures employed to extract the mean angle of attack from the available experimental data are discussed, and comments are made on the application of dynamic stall models in conjunction with 3D augmentation models on the rotating wind turbine blades.

Flutter performance of bend–twist coupled large-scale wind turbine blades

2016 ◽  
Vol 370 ◽  
pp. 149-162 ◽  
Author(s):  
Khazar Hayat ◽  
Alvaro Gorostidi Martinez de Lecea ◽  
Carlos Donazar Moriones ◽  
Sung Kyu Ha
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Turbine Blades ◽  
Wind Turbine Blades
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