Dynamic Structural Model of a Wind Turbine

2013 ◽  
pp. 135-148
Keyword(s):  
Wind Turbine ◽  
Structural Model ◽  
Dynamic Structural Model

Benchmark of a Novel Aero-Elastic Simulation Code for Small Scale VAWT Analysis

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
David Marten ◽  
Matthew Lennie ◽  
George Pechlivanoglou ◽  
Christian Oliver Paschereit ◽  
Alessandro Bianchini ◽  
...  
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Open Source ◽  
Structural Model ◽  
Element Model ◽  
Small Scale ◽  
Elastic Model ◽  
Element Analysis ◽  
Simulation Code ◽  
Highly Nonlinear

After almost 20 years of absence from research agendas, interest in the vertical axis wind turbine (VAWT) technology is presently increasing again, after the research stalled in the mid 90's in favor of horizontal axis wind turbines (HAWTs). However, due to the lack of research in past years, there are a significantly lower number of design and certification tools available, many of which are underdeveloped if compared to the corresponding tools for HAWTs. To partially fulfill this gap, a structural finite element analysis (FEA) model, based on the Open Source multiphysics library PROJECT::CHRONO, was recently integrated with the lifting line free vortex wake (LLFVW) method inside the Open Source wind turbine simulation code QBlade and validated against numerical and experimental data of the SANDIA 34 m rotor. In this work, some details about the newly implemented nonlinear structural model and its coupling to the aerodynamic solver are first given. Then, in a continuous effort to assess its accuracy, the code capabilities were here tested on a small-scale, fast-spinning (up to 450 rpm) VAWT. The study turbine is a helix shaped, 1 kW Darrieus turbine, for which other numerical analyses were available from a previous study, including the results coming from both a one-dimensional beam element model and a more sophisticated shell element model. The resulting data represented an excellent basis for comparison and validation of the new aero-elastic coupling in QBlade. Based on the structural and aerodynamic data of the study turbine, an aero-elastic model was then constructed. A purely aerodynamic comparison to experimental data and a blade element momentum (BEM) simulation represented the benchmark for QBlade aerodynamic performance. Then, a purely structural analysis was carried out and compared to the numerical results from the former. After the code validation, an aero-elastically coupled simulation of a rotor self-start has been performed to demonstrate the capabilities of the newly developed model to predict the highly nonlinear transient aerodynamic and structural rotor response.

scholarly journals Approximating the Cost-of-Living Index for a Storable Good

2018 ◽  
Vol 10 (2) ◽  
pp. 286-314 ◽  
Author(s):  
Matthew Osborne
Keyword(s):  
Regime Shift ◽  
Structural Model ◽  
Regime Shifts ◽  
Cost Of Living ◽  
Product Categories ◽  
Dynamic Structural Model ◽  
Fixed Base ◽  
Retail Prices ◽  
The Cost ◽  
Cost Of Living Index

This paper estimates a cost-of-living index using a dynamic structural model for two storable product categories. In each category, regime shifts to higher or lower retail prices are observed. Fixed-base indexes do a poor job of capturing changes in welfare after a regime shift, and deviate from the dynamic index by as much as 300 percent. I evaluate the extent to which two recently proposed indexes can approximate the model-derived index. These indexes improve welfare measurement and are straightforward to compute. The category’s competitive structure and features of the regime shift determine which of the two provides a better approximation. (JEL C43, C51, E31, L11)

A Dynamic Structural Model of Education and Skills Requirements for Careers in Information Systems

2011 ◽  
pp. 1-26 ◽  
Author(s):  
Glenn R. Lowry ◽  
Rodney L. Turner ◽  
Julie Fisher
Keyword(s):  
Professional Development ◽  
Information Systems ◽  
Structural Model ◽  
Soft Skills ◽  
Working Environment ◽  
Relative Importance ◽  
Relative Contribution ◽  
Dynamic Structural Model ◽  
Is Professionals ◽  
Career Progress

This chapter presents a dynamic structural model of the relative contribution and importance of education and skills required of information systems (IS) professionals. Model development took into account the technical skills found in many tertiary IS programs, other business-oriented academic studies, and soft skills sought by employers in new graduates. The model also includes features of the working environment which influence the career progress of IS graduates. Acknowledging the importance of these four areas, the authors present a second-order structural model that links these areas and compares the application of this model to IS students and decision makers who employ graduates. The model fits the data for the two groups and exhibits some unexpected outcomes in the area of soft skills, with students attributing more importance to soft skills than IS managers. The model was employed to identify gender differences in perceptions of the relative contribution and importance of education and skills required of IS professionals. The model also includes features of the working environment which influence the career progress of IS graduates. The model was used to describe how attitudes and perceptions of IS professionals change across career stages as measured by age groupings. Changes in perceptions across four major age groupings show significant differences with respect to these factors according to age groups and by inference, career stage. The model allows, with some confidence, a quantitative interpretation of the relative importance of the respective variables from the perspectives of the student and employer stakeholder groups toward the education and professional development of IS professionals. The model also suggests the presence of contrasting, gender-based quantitative views of the relative importance of the respective variables to the education and professional development of IS professionals.

scholarly journals Measuring the Impact of Promotions on Brand Switching When Consumers Are Forward Looking

2003 ◽  
Vol 40 (4) ◽  
pp. 389-405 ◽  
Author(s):  
Baohong Sun ◽  
Scott A. Neslin ◽  
Kannan Srinivasan
Keyword(s):  
Structural Model ◽  
Simulated Data ◽  
Real Data ◽  
Reduced Form ◽  
Coefficient Estimates ◽  
Dynamic Structural Model ◽  
Brand Switching ◽  
Form Model ◽  
Reduced Form Model ◽  
The Impact

Logit choice models have been used extensively to study promotion response. This article examines whether brand-switching elasticities derived from these models are overestimated as a result of rational consumer adjustment of purchase timing to coincide with promotion schedules and whether a dynamic structural model can address this bias. Using simulated data, the authors first show that if the structural model is correct, brand-switching elasticities are overestimated by stand-alone logit models. A nested logit model improves the estimates, but not completely. Second, the authors estimate the models on real data. The results indicate that the structural model fits better and produces sensible coefficient estimates. The authors then observe the same pattern in switching elasticities as they do in the simulation. Third, the authors predict sales assuming a 50% increase in promotion frequency. The reduced-form models predict much higher sales levels than does the dynamic structural model. The authors conclude that reduced-form model estimates of brand-switching elasticities can be overstated and that a dynamic structural model is best for addressing the problem. Reduced-form models that include incidence can partially, though not completely, address the issue. The authors discuss the implications for researchers and managers.

Numerical Analysis of Aeroelastic Responses of Wind Turbine Under Uniform Inflow

2020 ◽  
Author(s):  
Yang Huang ◽  
Decheng Wan
Keyword(s):  
Wind Turbine ◽  
Structural Model ◽  
Turbine Blades ◽  
Structural Deformation ◽  
Wind Turbine Blades ◽  
Wake Field ◽  
Wind Speeds ◽  
Inflow Condition ◽  
Blade Tip ◽  
Aeroelastic Simulations

Abstract With wind turbine blades becoming longer and slender, the influence of structural deformation on the aerodynamic performance of wind turbine cannot be ignored. In the present work, the actuator line technique that simplifies the wind turbine blades into virtual actual lines is utilized to simulate the aerodynamic responses of wind turbine and capture downstream wake characteristics. Moreover, the structural model based on a two-node, four degree-of-freedom (DOF) beam element is adopted for the deformation calculation of the wind turbine blades. By combing the actuator line technique and linear finite element theory, the aeroelastic simulations for the wind turbine blades can be achieved. The aeroelastic responses of NREL-5MW wind turbine under uniform wind inflow condition with different wind speeds are investigated. The aerodynamic loads, turbine wake field, blade tip deformations and blade root bending moments are analyzed to explore the influence of blade structural responses on the performance of the wind turbine. It is found that the power output of the wind turbine decreases when the blade deformation is taken into account. Significant asymmetrical phenomenon of the wake velocity is captured due to the deformation of the wind turbine blades.

Parametric Modeling and Simulation of Taper-Lock Connection in Wind Turbine Spindle Based on ANSYS

2012 ◽  
Vol 622-623 ◽  
pp. 1140-1142
Author(s):  
Li Mei Wu ◽  
Yong Zhao Li ◽  
Yan Rong Wang ◽  
Fei Yang
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Structural Model ◽  
Theoretical Data ◽  
Limit Load ◽  
Parametric Modeling ◽  
Stress And Strain ◽  
Finite Element Software ◽  
Load Conditions ◽  
Planet Carrier

Taking taper-lock Connection in Wind Turbine Spindle as research object, the paper analyzes the relativity of structural sizes and builds the parametric structural model by means of a way APDL. By using the non-liner finite element software ANSYS, the stress of taper-lock on the limit load conditions is analyzed, then contact stress and strain of the planet carrier and spindle are discussed. This is useful to the choice of assembly condition during taper-lock, planet carrier and spindle and providing theoretical data.

J1030205 Identification of Dynamic Structural Model Using Multiple Objective Optimization Method

2015 ◽  
Vol 2015 (0) ◽  
pp. _J1030205--_J1030205- ◽  
Author(s):  
Yuki MIMURA ◽  
Masayuki ICHIMONJI ◽  
Kyohei HIRAI ◽  
Toshikazu NAGATA ◽  
Toshiaki HIRATE ◽  
...  
Keyword(s):  
Structural Model ◽  
Optimization Method ◽  
Multiple Objective ◽  
Multiple Objective Optimization ◽  
Dynamic Structural Model

scholarly journals A Dynamic Structural Model for Estrogen Receptor-α Activation by Ligands, Emphasizing the Role of Interactions between Distant A and E Domains

2002 ◽  
Vol 10 (5) ◽  
pp. 1019-1032 ◽  
Author(s):  
Raphaël Métivier ◽  
Alexander Stark ◽  
Gilles Flouriot ◽  
Michael R Hübner ◽  
Heike Brand ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Structural Model ◽  
Estrogen Receptor Α ◽  
Dynamic Structural Model

Modelling leaf phototropism in a cucumber canopy

2008 ◽  
Vol 35 (10) ◽  
pp. 876 ◽  
Author(s):  
Katrin Kahlen ◽  
Dirk Wiechers ◽  
Hartmut Stützel
Keyword(s):  
Dry Matter ◽  
Structural Model ◽  
Shade Avoidance ◽  
Cucumis Sativus L ◽  
Dynamic Structural Model ◽  
L System ◽  
Matter Production ◽  
Greenhouse Cucumber ◽  
Left And Right ◽  
Avoidance Reactions

Leaf phototropism might have significant effects on the light interception, dry matter production and yield of cucumber (Cucumis sativus L.). The objective of the present study was to model the phototropism of leaves in a greenhouse cucumber canopy. The dynamic structural model of cucumber using a parametric L-system was extended to mimic the leaf movement induced by gradients in the local light environment of each leaf. The red to far-red (R : FR) ratio is known to be a driving force in shade avoidance reactions of plants. In the model, R : FR ratios on the left and right leaf half of each individual leaf lamina were calculated and the change in tropism angle per phyllochron was based on the R : FR gradient across the leaf halves. The tropism angle of a leaf describes the deviation of the present leaf azimuth from the initial leaf orientation, which is predefined by the phyllotaxis of the plant. Even in its simple form, the model simulated photo-morphogenic canopy responses.

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