Parametric study of the quasi-static response of wind turbines in downburst conditions using a numerical model

2022 ◽  
Vol 250 ◽  
pp. 113440
Author(s):  
Mostafa Ramadan Ahmed ◽  
Ashraf A. El Damatty ◽  
Kaoshan Dai ◽  
Ahmed Ibrahim ◽  
Wensheng Lu
Keyword(s):  
Numerical Model ◽  
Wind Turbines ◽  
Parametric Study ◽  
Static Response

Aeroelastic Analysis of NREL Wind Turbine

2017 ◽  
Author(s):  
Yaozhi Lu ◽  
Fanzhou Zhao ◽  
Loic Salles ◽  
Mehdi Vahdati
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Gas Turbines ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Measured Data ◽  
Forced Response ◽  
Cycle Fatigue ◽  
Aeroelastic Analysis

The current development of wind turbines is moving toward larger and more flexible units, which can make them prone to fatigue damage induced by aeroelastic vibrations. The estimation of the total life of the composite components in a wind turbine requires the knowledge of both low and high cycle fatigue (LCF and HCF) data. The first aim of this study is to produce a validated numerical model, which can be used for aeroelastic analysis of wind turbines and is capable of estimating the LCF and HCF loads on the blade. The second aim of this work is to use the validated numerical model to assess the effects of extreme environmental conditions (such as high wind speeds) and rotor over-speed on low and high cycle fatigue. Numerical modelling of this project is carried out using the Computational Fluid Dynamics (CFD) & aeroelasticity code AU3D, which is written at Imperial College and developed over many years with the support from Rolls-Royce. This code has been validated extensively for unsteady aerodynamic and aeroelastic analysis of high-speed flows in gas turbines, yet, has not been used for low-speed flows around wind turbine blades. Therefore, in the first place the capability of this code for predicting steady and unsteady flows over wind turbines is studied. The test case used for this purpose is the Phase VI wind turbine from the National Renewable Energy Laboratory (NREL), which has extensive steady, unsteady and mechanical measured data. From the aerodynamic viewpoint of this study, AU3D results correlated well with the measured data for both steady and unsteady flow variables, which indicated that the code is capable of calculating the correct flow at low speeds for wind turbines. The aeroelastic results showed that increase in crosswind and shaft speed would result in an increase of unsteady loading on the blade which could decrease the lifespan of a wind turbine due to HCF. Shaft overspeed leads to significant increase in steady loading which affects the LCF behaviour. Moreover, the introduction of crosswind could result in significant dynamic vibration due to forced response at resonance.

scholarly journals Dynamic Impedances of Offshore Rock-Socketed Monopiles

2019 ◽  
Vol 7 (5) ◽  
pp. 134 ◽  
Author(s):  
Rui He ◽  
Ji Ji ◽  
Jisheng Zhang ◽  
Wei Peng ◽  
Zufeng Sun ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Dynamic Stiffness ◽  
Large Diameter ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Thin Walled ◽  
Rock Parameters ◽  
Radiative Damping

With the development of offshore wind energy in China, more and more offshore wind turbines are being constructed in rock-based sea areas. However, the large diameter and thin-walled steel rock-socketed monopiles are very scarce at present, and both the construction and design are very difficult. For the design, the dynamic safety during the whole lifetime of the wind turbine is difficult to guarantee. Dynamic safety of a turbine is mostly controlled by the dynamic impedances of the rock-socketed monopile, which are still not well understood. How to choose the appropriate impedances of the socketed monopiles so that the wind turbines will neither resonant nor be too conservative is the main problem. Based on a numerical model in this study, the accurate impedances are obtained for different frequencies of excitation, different soil and rock parameters, and different rock-socketed lengths. The dynamic stiffness of monopile increases, while the radiative damping decreases as rock-socketed depth increases. When the weathering degree of rock increases, the dynamic stiffness of the monopile decreases, while the radiative damping increases.

A parametric study on the isolation of ground‐borne noise and vibrations in a building using a coupled numerical model

2008 ◽  
Vol 123 (5) ◽  
pp. 3260-3260
Author(s):  
Péter Fiala ◽  
Shashank Gupta ◽  
Geert Degrande ◽  
Fülöp Augusztinovicz
Keyword(s):  
Numerical Model ◽  
Parametric Study ◽  
Coupled Numerical Model

A parametric study of flexible micro-perforated panels with a patch-impedance numerical model

2017 ◽  
Vol 141 (5) ◽  
pp. 3797-3797
Author(s):  
Muttalip A. Temiz ◽  
Jonathan Tournadre ◽  
Ines Lopez Arteaga ◽  
Avraham Hirschberg
Keyword(s):  
Numerical Model ◽  
Parametric Study

Parametric Study and Comparison of Aerodynamics Momentum-Based Models for Straight-Bladed Vertical Axis Wind Turbines

2019 ◽  
Vol 45 (2) ◽  
pp. 729-741 ◽  
Author(s):  
Amin A. Mohammed ◽  
Hassen M. Ouakad ◽  
Ahmet Z. Sahin ◽  
Haitham M. S. Bahaidarah
Keyword(s):  
Wind Turbines ◽  
Parametric Study ◽  
Vertical Axis ◽  
Vertical Axis Wind Turbines

Numerical model for analysis of wind turbines under tornadoes

2020 ◽  
Vol 223 ◽  
pp. 111157
Author(s):  
Mohamed AbuGazia ◽  
Ashraf A. El Damatty ◽  
Kaoshan Dai ◽  
Wensheng Lu ◽  
Ahmed Ibrahim
Keyword(s):  
Numerical Model ◽  
Wind Turbines

scholarly journals Numerical Modelling and Simulation of the In-Plane Response of a Three-Storey Masonry-Infilled RC Frame Retrofitted with TRM

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Christiana A. Filippou ◽  
Nicholas C. Kyriakides ◽  
Christis Z. Chrysostomou
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Numerical Model ◽  
Parametric Study ◽  
Shear Capacity ◽  
Numerical Results ◽  
Rc Frame ◽  
Masonry Infill ◽  
Infilled Frame ◽  
Gap Opening

A numerical study was conducted to investigate the in-plane behavior of a masonry-infilled reinforced concrete (RC) frame retrofitted with textile-reinforced mortar (TRM). A two-dimensional finite element model was developed using DIANA finite element analysis (FEA) software to simulate the 2 : 3 scaled three-storey masonry-infilled RC frame retrofitted with TRM that was studied experimentally in the past. The three-storey structure used in the test was with a nonseismic design and detailing, and was subjected to in-plane displacement-control cyclic loading. The current study evaluates the capabilities of a representative numerical model to simulate the results of the experimental test, and after the calibration of the numerical model sensitivity analysis and parametric study were performed. In order to create an accurate numerical model, suitable constitutive models, based on the smeared crack approach, were used to characterize the nonlinear response of concrete, masonry infill, and TRM. The calibration of the models was based on the experimental results or inverse fitting based on optimizing the simulation of the response. The numerical model proved capable of simulating the in-plane behavior of the retrofitted masonry-infilled RC frame with good accuracy in terms of initial stiffness, and its deterioration, shear capacity, and cracking patterns. The calibrated model was then used to perform sensitivity analysis in order to examine the influence of infill-frame interface properties (tangential and normal stiffness) on the behavior of the retrofitted infilled frame. The numerical results showed that the gap opening is influenced significantly by the stiffness of the interface. In addition, a parametric study was performed in order to evaluate the importance of the full-bond condition between the TRM and the masonry-infilled RC frame. The numerical results indicate that the composite action between the TRM and the masonry-infilled RC frame improves the global stiffness and lateral resistance of the infilled frame, and it reduces the gap opening between the masonry infill and the RC frame.

Design of built-up steel beam-columns composed of two-channel sections

2020 ◽  
Author(s):  
George Iskander ◽  
Emam Soliman ◽  
Ezzeldin Yazeed Sayed-Ahmed
Keyword(s):  
Experimental Investigation ◽  
Numerical Model ◽  
Experimental Work ◽  
Parametric Study ◽  
Design Method ◽  
Steel Beam ◽  
Fe Model ◽  
Beam Columns ◽  
Initial Imperfections ◽  
Good Agreement

Built-up columns composed of two chords present an ideal design for long columns subject to high straining actions. The objective of this paper is to investigate the capacity of built-up columns composed of two-channel sections subjected to eccentric loading and propose a design method for them. A nonlinear numerical FE model is developed for these columns and verified against experimental investigation available from literature; the model includes both the geometric and materials nonlinearities along with the effect of initial imperfections. The model is used to perform a parametric study to investigate the effect of different factors on the built-up columns’ capacity. The results of the parametric study are also used to propose a design method for these columns. A limited experimental investigation is performed on two eccentrically loaded built-up columns, the results of experimental work showed good agreement with the numerical model results and the proposed design method.

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