Modeling and Optimization for the Dynamic Performance of Vertical-Axis Wind Turbine Composite Blades

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Sobhy Ghoneam ◽  
Ahmed Hamada ◽  
Taha Sherif
Keyword(s):  
Composite Material ◽  
Aspect Ratio ◽  
Wind Turbine ◽  
Dynamic Performance ◽  
Twist Angle ◽  
Design Parameters ◽  
Stacking Sequence ◽  
Modeling And Optimization ◽  
Composite Blade ◽  
Composite Blades

Abstract This article presents a study of modeling and optimization for the dynamic performance of wind turbine composite material blades and investigates the effects of composite material stacking sequence in addition to some design parameters such as twist angle (ɸ) and aspect ratio (AR) on the whole wind turbine performance. The two-stage Savonius rotor VAWT composite blades are designed and simulated within the solidworks simulation 2020 package. Modified mechanical parameters are introduced to improve the scalability, reliability, and accuracy of the developed models. The lamination plate theory is used to compute the equivalent mechanical properties for each composite blade. The finite element analyses (FEAs) are conducted to investigate the dynamic characteristics (frequency and associated mode shapes) of wind turbine models. Taguchi tools such as analysis of variance (ANOVA), signal-to-noise (S/N) ratio and additive model were employed to evaluate and obtain the significant factors and determine the optimal combination levels of wind turbine design parameters. Mathematical modeling based on response surface methodology (RSM) has been established. The analysis of results shows that the aspect ratio with a contribution of 48.08% had the dominant impact on the rotor performance followed by the stacking sequence and twist angle.

scholarly journals Aeroelastic Behavior of Low Aspect Ratio Metal and Composite Blades

1986 ◽  
Author(s):  
James F. White ◽  
Oddvar O. Bendiksen
Keyword(s):  
Aspect Ratio ◽  
Opposite Effect ◽  
Design Parameters ◽  
Aeroelastic Stability ◽  
Low Aspect Ratio ◽  
Supersonic Flutter ◽  
Type Mode ◽  
The Stability ◽  
Composite Blades ◽  
Plate Type

The aeroelastic stability of titanium and composite blades of low aspect ratio is examined over a range of design parameters, using a Rayleigh-Ritz formulation. The blade modes include a plate-type mode to account for chordwise bending. Chordwise flexibility is found to have a significant effect on the unstalled supersonic flutter of low aspect ratio blades, and also on the stability of tip sections of shrouded fan blades. For blades with a thickness of less than approximately four percent of chord, the chordwise, second bending, and first torsion branches are all unstable at moderately high supersonic Mach numbers. For composite blades, the important structural coupling between bending and torsion cannot be modeled properly unless chordwise bending is accounted for. Typically, aft fiber sweep produces beneficial bending-torsion coupling that is stabilizing, whereas forward fiber sweep has the opposite effect. By using crossed-ply laminate configurations, critical aeroelastic modes can be stabilized.

Dynamic Analysis of the Optimized Savonius Vertical Axis Wind Turbine Composite Blades

2021 ◽  
pp. 1-7
Author(s):  
Sobhy Ghoneam ◽  
Ahmed Hamada ◽  
Taha S. Sherif
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Vertical Axis ◽  
Mode Shapes ◽  
Speed Ratio ◽  
Damping Factor ◽  
Vertical Axis Wind Turbine ◽  
Composite Blades

Abstract This paper presents a comprehensive study of the dynamic behavior of small vertical axis wind turbines (VAWTs) based on local fabricated Savonius VAWTs, which is suitable for countries that have moderate wind speed. The merits of this design are cleanliness, silent, start-up under low wind speed, independent wind directions, adaptability and ease of manufacturing. Also, this paper presents an experimental validation study for the optimized Savonius VAWT. Four verification test configurations of the optimized VAWT composite blades are designed, simulated and fabricated of Glass – Polyester with different stacking sequence layout for each. Modified mechanical parameters are introduced to improve the scalability, reliability, and accuracy of the developed models. Based on wind energy conversion system basics, aerodynamic characteristics (tip speed ratio (λ) and coefficient of power (Cp)), dynamic characteristics (natural frequencies and mode shapes) of Savonius-rotor models are presented and simulated within SOLIDWORKS Simulation 2020 software. The dynamic characteristics such as frequency, mode shape and damping factor are extensively investigated using Fast Fourier Transformer (FFT) analyzer. The results show that the role of composite material blades in improving the dynamic performance of a wind turbine is significant.

Aeroelastic Behavior of Low-Aspect-Ratio Metal and Composite Blades

1987 ◽  
Vol 109 (2) ◽  
pp. 168-175 ◽  
Author(s):  
J. F. White ◽  
O. O. Bendiksen
Keyword(s):  
Aspect Ratio ◽  
Opposite Effect ◽  
Design Parameters ◽  
Aeroelastic Stability ◽  
Low Aspect Ratio ◽  
Supersonic Flutter ◽  
Type Mode ◽  
The Stability ◽  
Composite Blades ◽  
Plate Type

The aeroelastic stability of titanium and composite blades of low aspect ratio is examined over a range of design parameters, using a Rayleigh-Ritz formulation. The blade modes include a plate-type mode to account for chordwise bending. Chord-wise flexibility is found to have a significant effect on the unstalled supersonic flutter of low-aspect-ratio blades, and also on the stability of tip sections of shrouded fan blades. For blades with a thickness of less than approximately 4 percent of chord, the chordwise, second bending, and first torsion branches are all unstable at moderately high supersonic Mach numbers. For composite blades, the important structural coupling between bending and torsion cannot be modeled properly unless chordwise bending is accounted for. Typically, aft fiber sweep produces beneficial bending-torsion coupling that is stabilizing, whereas forward fiber sweep has the opposite effect. By using crossed-ply laminate configurations, critical aeroelastic modes can be stabilized.

scholarly journals Wind Turbine Blade Optimal Design Considering Multi-Parameters and Response Surface Method

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1639 ◽  
Author(s):  
Sang-Lae Lee ◽  
SangJoon Shin
Keyword(s):  
Optimal Design ◽  
Wind Turbine ◽  
Response Surface ◽  
Turbine Blade ◽  
Twist Angle ◽  
Wind Turbine Blade ◽  
Design Parameters ◽  
Aerodynamic Design ◽  
Regional Location ◽  
New Perspective

Within the framework of blade aerodynamic design, the maximum aerodynamic efficiency, power production, and minimum thrust force are the targets to obtain. This paper describes an improved optimization framework for blade aerodynamic design under realistic conditions, while considering multiple design parameters. The relationship between the objective function and the design parameters, such as the chord length, maximum chord, and twist angle, were obtained by using the second-order response surface methodology (RSM). Moreover, the identified parameters were organized to optimize the aerodynamic design of the blades. Furthermore, the initial and optimized blade geometries were compared and showed that the performance of the optimized blade improved significantly. In fact, the efficiency was increased by approximately 10%, although its thrust was not varied. In addition, to demonstrate the improvement in the resulting optimized blades, the annual energy production (AEP) was estimated when installed in a specific regional location. The result showed a significant improvement when compared to the baseline blades. This result will be extended to a new perspective approach for a more robust optimal design of a wind turbine blade.

The Dynamic Performance of a Composite Blade from a 5kW Wind Turbine Part II: Predicted Blade Response

2002 ◽  
Vol 26 (5) ◽  
pp. 273-286 ◽  
Author(s):  
M. E. Bechly ◽  
P. D. Clausen
Keyword(s):  
Wind Turbine ◽  
Dynamic Performance ◽  
Dynamic Equations ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Structural Dynamic ◽  
Composite Blade ◽  
Blade Tip ◽  
Blade Model ◽  
Computational Predictions

This paper presents analytical and computational predictions of the performance of an operating 2.5 m long composite wind turbine blade and compares these predictions with the results of detailed measurements. Part 1 of this paper describes in detail the important aspects of the 5 kW wind turbine, the experimental equipment and data acquisition procedures and presents and discusses some of the results from the experimental data. Here the analytical methodology of Eggleston and Stoddard (1987) and the solutions from the computational wind turbine software package Bladed, were used to predict the performance of the blade for a particular set of experimental conditions. The solutions of Eggleston and Stoddard, where only the first order dynamic equations of a simplified blade model are solved, underestimate the root flapwise moment, streamwise blade tip deflection and lead-lag tip deflection, but gave fairly accurate predictions for the blade lead lag moment. The turbine's structural dynamics within Bladed used a more accurate model of the blade and solved the structural dynamic equations by implementing modal analysis. The results gave root flapwise moment of the same order as those determined from the measurements, close agreement with the measured lead-lag moment, a slight underprediction of the flapwise tip deflection and large under prediction of the lead-lag tip deflection. The under prediction of the lead-lag deflection by both methods is likely to be due to the uncoupling of the lead-lag and flapping motions, and the unusual shape of the blade close to its root connection.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

Front steering design guidelines formulation for e-scooters considering the influence of sitting and standing riders on self-stability and safety performance

2021 ◽  
pp. 095440702199217
Author(s):  
Milan Paudel ◽  
Fook Fah Yap
Keyword(s):  
Preventive Measures ◽  
Recent Trend ◽  
Dynamic Performance ◽  
Design Guidelines ◽  
Safety Performance ◽  
Design Parameters ◽  
Single Track ◽  
Standing Posture ◽  
Last Mile ◽  
Current Design

E-scooters are a recent trend and are viewed as a sustainable solution to ease the first and last mile problem in modern transportation. However, an alarming rate of accidents, injuries, and fatalities have caused a significant setback for e-scooters. Many preventive measures and legislation have been put on the e-scooters, but the number of accidents and injuries has not reduced considerably. In this paper, the current design approach of e-scooters has been analyzed, and the most common range of design parameters have been identified. Thereafter, validated mathematical models have been used to quantify the performance of e-scooters and relate them with the safety aspects. Both standing and seated riders on e-scooters have been considered, and their influence on the dynamic performance has been analyzed and compared with the standard 26-in wheel reference safety bicycle. With more than 80% of the accidents and injuries occurring from falling or colliding with obstacles, this paper tries to correlate the dynamics of uncontrolled single-track vehicles with the safety performance of e-scooters. The self-stability, handling, and braking effect have been considered as major performance matrices. The analysis has shown that the current e-scooter designs are not as stable as the reference safety bicycle. Moreover, these e-scooters have been found unstable within the most common range of legislated riding velocity. The results corroborate with the general perception that the current designs of e-scooters are less stable, easy to lose control, twitchy, or wobbly to ride. Furthermore, the standing posture of the rider on the e-scooter has been found dangerous while braking to avoid any disturbances such as potholes or obstacles. Finally, the front steering design guidelines have been proposed to help modify the current design of e-scooters to improve the dynamic performance, hence the safety of the e-scooter riders and the surroundings.

scholarly journals Clogging sensitivity of flow distributors designed for radially elongated hexagonal pillar array columns: a computational modelling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farideh Haghighi ◽  
Zahra Talebpour ◽  
Amir Sanati-Nezhad
Keyword(s):  
Pressure Drop ◽  
Aspect Ratio ◽  
Contact Zone ◽  
Separation Efficiency ◽  
Fluid Dynamic ◽  
Computational Modelling ◽  
Channel Width ◽  
Fluid Distribution ◽  
Design Parameters ◽  
Pillar Array

AbstractFlow distributor located at the beginning of the micromachined pillar array column (PAC) has significant roles in uniform distribution of flow through separation channels and thus separation efficiency. Chip manufacturing artifacts, contaminated solvents, and complex matrix of samples may contribute to clogging of the microfabricated channels, affect the distribution of the sample, and alter the performance of both natural and engineered systems. An even fluid distribution must be achieved cross-sectionally through careful design of flow distributors and minimizing the sensitivity to clogging in order to reach satisfactory separation efficiency. Given the difficulty to investigate experimentally a high number of clogging conditions and geometries, this work exploits a computational fluid dynamic model to investigate the effect of various design parameters on the performance of flow distributors in equally spreading the flow along the separation channels in the presence of different degrees of clogging. An array of radially elongated hexagonal pillars was selected for the separation channel (column). The design parameters include channel width, distributor width, aspect ratio of the pillars, and number of contact zone rows. The performance of known flow distributors, including bifurcating (BF), radially interconnected (RI), and recently introduced mixed-mode (MMI) in addition to two new distributors designed in this work (MMII and MMIII) were investigated in terms of mean elution time, volumetric variance, asymmetry factors, and pressure drop between the inlet and the monitor line for each design. The results show that except for pressure drop, the channel width and aspect ratio of the pillars has no significant influence on flow distribution pattern in non-clogged distributors. However, the behavior of flow distributors in response to clogging was found to be dependent on width of the channels. Also increasing the distributor width and number of contact zone rows after the first splitting stage showed no improvement in the ability to alleviate the clogging. MMI distributor with the channel width of 3 µm, aspect ratio of the pillars equal to 20, number of exits of 8, and number of contact zones of 3 exhibited the highest stability and minimum sensitivity to different degrees of clogging.

Sign in / Sign up

Export Citation Format

Share Document