Design of Viscous Dynamic Vibration Absorber for a Vertical-Axis Wind Turbine

2012 ◽  
Author(s):  
Georges Kouroussis ◽  
Lassaad Ben Fekih ◽  
Jean-Yves Bottieau ◽  
Olivier Verlinden
Keyword(s):  
Wind Turbine ◽  
Low Cost ◽  
Vibration Reduction ◽  
Vertical Axis ◽  
Element Model ◽  
Mode Shapes ◽  
Vibration Absorber ◽  
Vertical Axis Wind Turbine ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration

This paper presents the investigations brought to fruition for the design of a dynamic vibration absorber (DVA) for vertical-axis wind turbine. A first step is devoted to the experimental analysis of the structure, by seeking its modal behaviour in low frequency range. A numerical model of the turbine system consisting of finite elements is developed. Their dynamics and geometrical characteristics are updated, by fitting the first three bending numerical mode shapes with the experimental ones. Finally, a mathematical model of DVA is implemented and the vibration reduction is evaluated with the help of the updated finite element model, considering the modal decomposition of the structure. The results exhibit significant vibration reduction performance evidencing this kind of device. A tuneable anti-vibration device is then designed, with a purpose of simplicity and low-cost production. The possible non-linearity of the DVA is also studied, by comparing behaviours of linear and quadratic selected dampers.

scholarly journals Design of Vertical Axis Wind Turbine Darrieus Type (H- Darrieus Rotor) of 0.20 KW from the Software Topsolid

2020 ◽  
pp. 52-70
Author(s):  
Hagninou E. V. Donnou ◽  
Drissa Boro ◽  
Donald Abode ◽  
Brunel Capo-Chichi ◽  
Aristide B. Akpo
Keyword(s):  
Wind Turbine ◽  
Permanent Magnets ◽  
Aerodynamic Force ◽  
Low Cost ◽  
Coastal Region ◽  
Vertical Axis ◽  
Digital Design ◽  
Three Dimensions ◽  
Geometrical Shape ◽  
Vertical Axis Wind Turbine

The design of a vertical axis wind turbine (Darrieus type) adapted to the site of Cotonou in the coastal region of Benin was investigated. The statistical study of winds based on the Weibull distribution was carried out on hourly wind data measured at 10 m above the ground by the Agency for the Safety of Air Navigation in Africa and Madagascar (ASECNA) over the period from January 1981 to December 2014. The geometrical and functional parameters of the wind turbine were determined from different models and aerodynamic approaches. The digital design and assembly of the wind turbine components were carried out using the TOPSOLID software. The designed wind turbine has a power of 200W. It is equipped with a synchronous generator with permanent magnets and has three wooden blades with NACA 0015 profile. The optimal coefficient of lift and drag were estimated respectively at 0.7832 and 0.01578. The blades are characterized by an optimum angle of attack estimated at 6.25° with a maximum fineness of 49.63. Their length is 4 m and the maximum thickness is estimated at 0.03 m with a chord of 0.20 m. The volume and mass are respectively equal to 0.024 m3 and 36 kg. The aerodynamic stall occurs at an attack angle of 14.25°. The aerodynamic force exerted on these blades is estimated to be 240 N. The aerodynamic stresses exerted on the rotor are estimated at 15 864 504 Pa and the solidity at 0.27. The efficiency of the wind turbine is 0.323. From TOPSOLID, the geometrical shape of each component of the wind turbine is represented in three dimensions. The assembly allowed to visualizing the wind turbine after export via its graphical interface. The quantity of annual energy produced by the wind turbine was estimated at 0.85 MWh. This study is the first to be carried out in the study area and could reduce the technological dependence of vertical axis wind turbines and their import for low cost energy production.

scholarly journals Application of Adaptive Tuned Magneto-Rheological Elastomer for Vibration Reduction of a Plate by a Variable-Unbalance Excitation

2020 ◽  
Vol 10 (11) ◽  
pp. 3934 ◽  
Author(s):  
Un-Chang Jeong
Keyword(s):  
Vibration Reduction ◽  
Excitation Frequency ◽  
Target Object ◽  
Vibration Absorber ◽  
Magnetorheological Elastomer ◽  
Dynamic Vibration Absorber ◽  
Mass Part ◽  
Dynamic Vibration ◽  
Frequency Excitation ◽  
Magneto Rheological

The present study on vibration reduction in systems wherein the excitation frequency is variable designed and fabricated a magnetorheological elastomer (MRE)-based tunable dynamic vibration absorber and evaluated its performance in an experimental manner. The design of an MRE-based adaptive tuned dynamic vibration absorber (ATDVA) involves designing two parts: stiffness and mass. Before designing the MRE-based ATDVA, this study determined the resonance frequency of a target object for vibration reduction. For the design of the ATDVA’s stiffness part, the thickness of specimens was determined by measuring the rate of variation of the MRE’s shear modulus with respect to the MRE’s thickness. The design of the mass part was optimized using sensitivity analysis and genetic algorithms after the derivation of formulas for its magnetic field and mass. Further, upon the application of an electric current to the MRE, its stiffness was measured so that the stiffness of the designed MRE-based ATDVA could be tuned accordingly. Finally, the vibration-reducing performance of the MRE-based ATDVA was evaluated to determine the applicability of the vibration absorber under the condition of variable-frequency excitation.

scholarly journals Aerodynamics and Modal Analysis for the Combined Vane type Vertical Axis Wind Turbine

2018 ◽  
Vol 7 (4.38) ◽  
pp. 1395 ◽  
Author(s):  
Kadhim H. Suffer ◽  
Yassr Y. Kahtan ◽  
Zuradzman M. Razlan
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Turbine Rotor ◽  
Mode Shapes ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Starting Torque

The present global energy economy suggests the use of renewable sources such as solar, wind, and biomass to produce the required power. The vertical axis wind turbine is one of wind power applications. Usually, when the vertical axis wind turbine blades are designed from the airfoil, the starting torque problem begins. The main objective of this research is to numerically simulate the combination of movable vanes of a flat plate with the airfoil in a single blade configuration to solve the starting torque problem. CFD analysis in ANSYS-FLUENT and structural analysis in ANSYS of combined blade vertical axis wind turbine rotor has been undertaken. The first simulation is carried out to investigations the aerodynamic characteristic of the turbine by using the finite volume method. While the second simulation is carried out with finite element method for the modal analysis to find the natural frequencies and the mode shape in order to avoid extreme vibration and turbine failure, the natural frequencies, and their corresponding mode shapes are studied and the results were presented with damping and without damping for four selected cases. The predicted results show that the static pressure drop across the blade increase in the active blade side because of the vanes are fully closed and decrease in the negative side because of the all the vanes are fully open. The combined blade helps to increase turbine rotation and so, thus, the power of the turbine increases. While the modal results show that until the 5th natural frequency the effect of damping can be neglected. The predicted results show agreement with those reported in the literature for VAWT with different blade designs.   

Exact Optimization of a Three-Element Dynamic Vibration Absorber: Minimization of the Maximum Amplitude Magnification Factor

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Osamu Nishihara
Keyword(s):  
Maximum Amplitude ◽  
Resonance Curve ◽  
Element Model ◽  
Optimality Criteria ◽  
Simultaneous Equations ◽  
Vibration Absorber ◽  
Magnification Factor ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Numerical Computing

In this study, the maximum amplitude magnification factor for a linear system equipped with a three-element dynamic vibration absorber (DVA) is exactly minimized for a given mass ratio using a numerical approach. The frequency response curve is assumed to have two resonance peaks, and the parameters for the two springs and one viscous damper in the DVA are optimized by minimizing the resonance amplitudes. The three-element model is known to represent the dynamic characteristics of air-damped DVAs. A generalized optimality criteria approach is developed and adopted for the derivation of the simultaneous equations for this design problem. The solution of the simultaneous equations precisely equalizes the heights of the two peaks in the resonance curve and achieves a minimum amplitude magnification factor. The simultaneous equations are solvable using the standard built-in functions of numerical computing software. The performance improvement of the three-element DVA compared to the standard Voigt type is evaluated based on the equivalent mass ratios. This performance evaluation is highly accurate and reliable because of the precise formulation of the optimization problem. Thus, the advantages of the three-element type DVA have been made clearer.

The Straight-Bladed Morphing Vertical Axis Wind Turbine

2016 ◽  
Author(s):  
David MacPhee ◽  
Asfaw Beyene
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Low Cost ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Vertical Axis Wind Turbine ◽  
Pitch Control ◽  
Control Schemes ◽  
Horizontal Axis Wind Turbines ◽  
Novel Concept

Blade pitch control has been extremely important for the development of Horizontal-Axis Wind Turbines (HAWTs), allowing for greater efficiency over a wider range of operational regimes when compared to rigid-bladed designs. For Vertical-Axis Wind Turbines (VAWTs), blade pitching is inherently more difficult due to a dependence of attack angle on turbine armature location, shaft speed, and wind speed. As a result, there have been very few practical pitch control schemes put forward for VAWTs, which may be a major reason why this wind turbine type enjoys a much lower market share as compared to HAWTs. To alleviate this issue, the flexible, straight-bladed vertical-axis turbine is presented, which can passively adapt its geometry to local aerodynamic loadings and serves as a low-cost blade pitch control strategy increasing efficiency and startup capabilities. Using two-dimensional fluid-structure action simulations, this novel concept is compared to an identical rigid one and is proven to be superior in terms of power coefficient due to decreased torque minima. Moreover, due to the flexible nature of the blades, the morphing turbine achieves less severe oscillatory loadings. As a result, the morphing blade design is expected to not only increase efficiency but also system longevity without additional system costs usually associated with active pitch control schemes.

10 kw Vertical Axis Wind Turbine Spindle Design and Optimization

2014 ◽  
Vol 487 ◽  
pp. 429-434 ◽  
Author(s):  
Qiao Mei Li ◽  
Yang Cao ◽  
Guo Qing Wu ◽  
Xing Hua Chen ◽  
Yan Hua Cao
Keyword(s):  
Wind Turbine ◽  
Vibration Mode ◽  
Vertical Axis ◽  
Element Model ◽  
High Load ◽  
Design Parameters ◽  
Vertical Axis Wind Turbine ◽  
Dead Weight ◽  
Design And Optimization ◽  
The Finite Element Model

The spindle of a 10 kw vertical axis wind turbine is designed in this paper, and the relevant geometric parameters is given, and build the geometry of the finite element model. Calculation of the spindle under wind load and dead weight , and analyse the spindle Von Mess stress, deformation nephogram, and give the former six order vibration mode of the spindle. Through the analysis, Then the design parameters of the spindle are optimized. and the optimized structure of spindle has been got. optimized spindle is in lower quality, more satisfy the requirement of wind turbine running under high load at the same time .

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