Influence of Blade Solidity on Marine Hydrokinetic Turbines

2012 ◽  
Author(s):  
Michael Jonson ◽  
John Fahnline ◽  
Erick Johnson ◽  
Matthew Barone ◽  
Arnold Fontaine
Keyword(s):  
Marine Ecosystem ◽  
Turbine Blades ◽  
Electrical Power ◽  
Well Being ◽  
Wind Turbine Blades ◽  
Blade Vibration ◽  
Radiated Noise ◽  
Hydrokinetic Turbines ◽  
Horizontal Axis Wind Turbines ◽  
Marine Hydrokinetic

Marine hydrokinetic (MHK) devices are currently being considered for the generation of electrical power in marine tidal regions. Turbulence generated in the boundary layers of these channels interacts with a turbine to excite the blades into low-to mid-frequency vibration. Additionally, the self-generated turbulent boundary layer on the turbine blade excites its trailing edge into vibration. Both of these hydrodynamic sources generate radiated noise. Being installed in a marine ecosystem, the noise generated by these MHK devices may affect the fish and marine mammal well-being. Since this MHK technology is relatively new, much of the design practice follows that from conventional horizontal axis wind turbines. In contrast to other underwater turbomachines like conventional merchant ships that have solid blades, wind turbine blades are made of hollow fiberglass composites. This paper systematically investigates the contrast of this design detail on the blade vibration and radiated noise for a particular MHK turbine design.

Edgewise vibration reduction of small size wind turbine blades using shunt damping

2019 ◽  
Vol 26 (3-4) ◽  
pp. 186-199
Author(s):  
Hamed Biglari ◽  
Vahid Fakhari
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Vibration Reduction ◽  
Wind Turbine Blades ◽  
Lagrange Method ◽  
Blade Vibration ◽  
Mass Damper ◽  
Horizontal Axis Wind Turbines ◽  
Shunt Damping

Edgewise vibration in wind turbine blades is one of the important factors that results in reducing the performance of wind turbines. Therefore, control or reduction of the mentioned vibrations can be of great help in increasing the efficiency of wind turbines. In this paper, the shunt damping method is proposed to reduce the edgewise blade vibration of horizontal axis wind turbines. For this purpose, partial differential equations governing dynamics of the system are derived using the Lagrange method. These equations are completely nonlinear and linearization is not performed to avoid possible errors in the analysis. In order to evaluate the effectiveness of the proposed shunt damping method in vibration reduction of the wind turbine blade, obtained results by applying shunt damping method are compared with corresponding results obtained by employing a conventional method known as a tuned mass damper (TMD). For better comparison, by considering proper cost functions, the shunt damper and TMD parameters are optimized using a genetic algorithm. Finally, the effectiveness of optimized shunt damper in vibration reduction of the blade is compared with optimized TMD by presenting simulation results.

scholarly journals Simulation of Glass Fiber Reinforced Polypropylene Nanocomposites for Small Wind Turbine Blades

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 622
Author(s):  
Yasser Elhenawy ◽  
Yasser Fouad ◽  
Haykel Marouani ◽  
Mohamed Bassyouni
Keyword(s):  
Wind Turbine ◽  
Glass Fiber ◽  
Turbine Blades ◽  
Small Scale ◽  
Fiber Reinforced ◽  
Wind Turbine Blades ◽  
Element Analysis ◽  
Glass Fiber Reinforced ◽  
Horizontal Axis Wind Turbines ◽  
Multi Walled Carbon Nanotubes

This study aims to evaluate the effect of functionalized multi-walled carbon nanotubes (MWCNTs) on the performance of glass fiber (GF)-reinforced polypropylene (PP) for wind turbine blades. Support for theoretical blade movement of horizontal axis wind turbines (HAWTs), simulation, and analysis were performed with the Ansys computer package to gain insight into the durability of polypropylene-chopped E-glass for application in turbine blades under aerodynamic, gravitational, and centrifugal loads. Typically, polymer nanocomposites are used for small-scale wind turbine systems, such as for residential applications. Mechanical and physical properties of material composites including tensile and melt flow indices were determined. Surface morphology of polypropylene-chopped E-glass fiber and functionalized MWCNTs nanocomposites showed good distribution of dispersed phase. The effect of fiber loading on the mechanical properties of the PP nanocomposites was investigated in order to obtain the optimum composite composition and processing conditions for manufacturing wind turbine blades. The results show that adding MWCNTs to glass fiber-reinforced PP composites has a substantial influence on deflection reduction and adding them to chopped-polypropylene E-glass has a significant effect on reducing the bias estimated by finite element analysis.

Optimization of Wind Turbine Blades Using Lifting Surface Method and Genetic Algorithm

2011 ◽  
Author(s):  
Xin Shen ◽  
Xiao-cheng Zhu ◽  
Zhao-hui Du
Keyword(s):  
Genetic Algorithm ◽  
Design Method ◽  
Turbine Blades ◽  
Optimization Method ◽  
Efficient Design ◽  
Wind Turbine Blades ◽  
Surface Method ◽  
Lifting Surface ◽  
Horizontal Axis Wind Turbines ◽  
Wake Model

This paper describes an optimization method for the design of horizontal axis wind turbines using the lifting surface method as the performance prediction model and a genetic algorithm for optimization. The aerodynamic code for the design method is based on the lifting surface method with a prescribed wake model for the description of the wake. A micro genetic algorithm handles the decision variables of the optimization problem such as the chord and twist distribution of the blade. The scope of the optimization method is to achieve the best trade off of the following objectives: maximum of annual energy production and minimum of blade loads including thrust and blade rood flap-wise moment. To illustrate how the optimization of the blade is carried out the procedure is applied to NREL Phase VI rotor. The result shows the optimization model can provide a more efficient design.

Design and Research on a Automatic Cleaning Device of Wind Turbine Blades

2013 ◽  
Vol 448-453 ◽  
pp. 3472-3475
Author(s):  
Tai Lv ◽  
Qiang Wang
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Pressure Field ◽  
Turbine Blades ◽  
Positive Pressure ◽  
Wind Turbine Blades ◽  
Cleaning Device ◽  
Horizontal Axis Wind Turbines ◽  
Ash Deposit ◽  
Fluent Software

Aiming at ash deposit problem of wind turbine blades, a cleaning device for 10kW horizontal axis wind turbines was designed by applying the mechanism that ash deposit on blades surface was purged by high-speed flows from nozzle. Using fluent software, a numerical simulation was carried out in cleaning device, and its pressure field and velocity field in different cross section of wind turbine blades were simulated under cleaning state. The results showed that positive pressure zone created by cleaning device was formed on blades surface, and high-speed airflow purging blades surface was formed. As a result, the purpose of cleaning is achieved.

Digital Speckle Photogrammetry Techniques Applied to Monitoring High Temperature Steam Pipes

2006 ◽  
Author(s):  
Andrew Morris ◽  
John Dear ◽  
Miltiadis Kourmpetis ◽  
Alexander Fergusson ◽  
Amit Puri
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Electrical Power ◽  
Monitoring Methods ◽  
Wind Turbine Blades ◽  
Image Capture ◽  
Power Stations ◽  
Digital Speckle ◽  
Critical Components ◽  
High Temperature Steam

Digital Speckle Photogrammetry (DSP) is proving to be a very useful technique for studying, in the laboratory, the distribution of strain about cracks and other defects in stressed specimens. This non-contact technique is able to resolve strain gradients over a small physical area, for example across a weld heat affected zone. The technique has good potential for use as a condition monitoring tool for a variety of components in electrical power stations. In addition this measurement technique could also be applied to monitor the integrity of critical components of newer generation plant, such as wind turbine generator blades. There are, however, many installation problems to be overcome. For example, there is the need to have regard for the hostile environment in steam generating plant and the demanding conditions to which wind turbine blades are subjected. Ideally the outputs from individual DSP sensors would be used for continuous remote monitoring. However, DSP measurements can also be useful each time the plant is shut down during a plant outage; which would be used to complement data from existing proven rugged monitoring methods. This paper describes ongoing work to develop a ruggedised digital speckle ‘sensor’ and associated image capture system.

Single and Multi Objective CFD Optimization of Horizontal Axis Wind Turbines

2011 ◽  
Author(s):  
Fabio De Bellis ◽  
Luciano A. Catalano
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Computational Cost ◽  
Three Dimensional ◽  
Steam Turbines ◽  
Wind Turbine Blades ◽  
Multi Objective ◽  
Horizontal Axis Wind Turbines ◽  
Cfd Optimization

In spite of the enlarging interest in wind turbines development, the design optimization of wind turbine blades has not been studied in the past as gas or steam turbines optimization. Due to its reduced computational cost, Blade Element Momentum (BEM) method has been employed up to now to estimate the power output of the turbine. However, BEM method is not able to predict complex three dimensional flow fields or the performance of profiles for which drag and lift coefficients are not available. Theoretically, Computational Fluid Dynamics (CFD) can be more useful in these cases, but at the price of a much higher overall computational cost. In a past work, the authors developed and validated a simplified CFD process (including meshing) capable to assess the aerodynamic loads acting on a wind turbine with acceptable computational resources. Starting from that, in this work a full 3D CFD optimization of a small wind turbine is presented, both with constrained single- and multi-objective. Twist and chord distributions of a single blade have been varied keeping fixed the aerodynamic profile, and the obtained optimums have been compared with a benchmark case. The results demonstrate that CFD optimization can be effectively employed in a wind turbine optimization. As expected, stalled conditions of the blade are more likely to be improved than those characterized by attached flow. Future works will focus on multi-disciplinary optimization and will include also aerodynamic profile variation.

Out-of-Plane Nonlinear Dynamic Analysis of Wind Turbine Blades

2014 ◽  
Author(s):  
Venkatanarayanan Ramakrishnan ◽  
Brian F. Feeny
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Nonlinear Dynamic Analysis ◽  
Single Mode ◽  
Equation Of Motion ◽  
Wind Turbine Blades ◽  
Blade Vibration ◽  
Premature Failure ◽  
Lagrange Formulation ◽  
Out Of Plane

In this work, the out-of-plane equation of motion of a wind turbine blade modeled as a beam is developed using the Lagrange formulation. The modeling of aerodynamic loads is done with the blade element momentum theory. The equation of motion has combined effects of parametric and direct excitations and is reduced to a single mode. Perturbation analysis based on previous work shows how various terms affect the steady-state responses near resonance. Numerical simulations using parameters from a real turbine, reveal that these resonance become critical as the blades increase in size. The out-of-plane vibration model shows resonances that would not be expected by blade designers without analysis and modeling techniques presented in this work. The influence of these superharmonic blade vibration responses on the increased loads on the gearbox components would provide insight into premature failure of wind turbine blades and gearboxes.

Numerical analysis of the influence of inertial loading over morphing trailing edge devices

2018 ◽  
Vol 29 (18) ◽  
pp. 3533-3549 ◽  
Author(s):  
Nicolás G Tripp ◽  
Aníbal E Mirasso ◽  
Sergio Preidikman
Keyword(s):  
Wind Turbine ◽  
State Of The Art ◽  
Turbine Blades ◽  
External Loading ◽  
Wind Turbine Blades ◽  
Trailing Edge ◽  
Blade Vibration ◽  
Simple Estimation ◽  
Design Requirements ◽  
Inertial Loading

Larger and more flexible wind turbine blades are currently being manufactured. Those highly flexible blades suffer from loading of aeroelastic nature which increases the fatigue damage. Smart blade concepts are being developed to reduce the aerodynamic loading. The state of the art favors the discrete deformable trailing edge concept. Many authors have reported adequate performance of this type of actuators in reducing the blade vibrations. However, the question of whether the actuator can maintain its authority under strong external loading remains still answered. To solve this question, actuator models that include the loading produced by the blade vibration are required. In this article, a smart morphing trailing edge model is presented that includes the inertial forces produced by the blade dynamics. The model is applied to a commercial actuator and the influence of its parameters is analyzed. Finally, a simple estimation of the inertial loading produced by a 35-m wind turbine blade at the flutter instability condition is analyzed to understand the design requirements of this type of systems.

Adaptive Composites for Load Control in Marine Turbine Blades

2017 ◽  
Author(s):  
Ramona B. Barber ◽  
Craig S. Hill ◽  
Pavel F. Babuska ◽  
Alberto Aliseda ◽  
Richard Wiebe ◽  
...  
Keyword(s):  
Composite Structures ◽  
Turbine Blades ◽  
Frp Composites ◽  
Hydrokinetic Turbines ◽  
Hydrokinetic Turbine ◽  
Marine Hydrokinetic ◽  
Strength And Stiffness ◽  
Adaptive Composites ◽  
Composite Blades ◽  
Adaptive Composite

Marine hydrokinetic turbines typically operate in harsh, strongly dynamic conditions. All components of the turbine system must be extremely robust and able to withstand large and constantly varying loads; the long and relatively slender blades of marine turbines are especially vulnerable. Because of this, modern marine turbine blades are increasingly constructed from fiber reinforced polymer (FRP) composites. Composite materials provide superior strength- and stiffness-to-weight ratios and improved fatigue and corrosion resistance compared to traditional metallic alloys. Additionally, it is possible to tailor the anisotropic properties of FRP composites to create an adaptive pitch mechanism that will adjust the load on the turbine in order to improve system performance, especially in off-design or varying flow conditions. In this work, qualitative fundamentals of composite structures are discussed with regards to the design of experimental scale adaptive pitch blades. The load-deformation relationship of flume-scale adaptive composite blades are characterized experimentally under static loading conditions, and dynamic loading profiles during flume testing are reported. Two sets of adaptive composite blades are compared to neutral pitch composite and rigid aluminum designs. Experimental results show significant load adjustments induced through passive pitch adaptation, suggesting that adaptive pitch composite blades could be a valuable addition to marine hydrokinetic turbine technology.

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