14 research outputs found
Multi-element ducts for ducted wind turbines: A numerical study
No full textMulti-element ducts are used to improve the aerodynamic performance of ducted wind turbines (DWTs). Steady-state, two-dimensional computational fluid dynamics (CFD) simulations are performed for a multi-element duct geometry consisting of a duct and a flap; the goal is to evaluate the effects on the aerodynamic performance of the radial gap length and the deflection angle of the flap. Solutions from inviscid and viscous flow calculations are compared. It is found that increasing the radial gap length results in an augmentation of the total thrust generated by the DWT, whereas a larger deflection angle has an opposite effect. Reasonable to good agreement is seen between the inviscid and viscous flow calculations, except for multi-element duct configurations characterized by large flap deflection angles. The viscous effects become stronger at large flap deflection angles, and the inviscid calculations are incapable of taking this phenomenon into account.</p
Sensitivity analysis and Bayesian calibration of a dynamic wind farm control model: FLORIDyn
No full textFLORIDyn is a parametric control-oriented dynamic model suitable to predict the dynamic wake interactions between wind turbines in a wind farm. In order to improve the accuracy of FLORIDyn, this study proposes to calibrate the tuning parameters present in the model by employing a probabilistic setting using the UQ4WIND framework. The strategy relies on constructing a surrogate model (based on polynomial chaos expansion), which is then used to perform both global sensitivity analysis and Bayesian calibration. For our analysis, a nine wind turbine configuration in a yawed setting constitutes the test case. The results of sensitivity analysis offer valuable insight into the time-dependent influence of the model parameters onto the model output. The model parameter tied to the turbine efficiency appear to be the most sensitive parameter affecting the model output. The calibrated FLORIDyn model using the Bayesian approach yield predictions much closer to the measurement data, which is equipped with an uncertainty estimate.Team Jan-Willem van Wingerde
How does yawed inflow affect the performance of ducted wind turbines?
No full textDucted Wind Turbines (DWTs) are used for energy harvesting in urban areas where the flow is non-uniform in comparison to the free-field because of the presence of buildings or other surface discontinuities. For this reason, the aerodynamic performance and far-field noise of DWTs in yawed inflow conditions must be characterized. Both the aerodynamic and the acoustic fields are dependent on the geometry of the duct. In this study, the effect of the duct geometry is analysed with high fidelity numerical simulations carried out with the lattice-Boltzmann method.Wind Energ
Improving O&M Simulations by Integrating Vessel Motions for Floating Wind Farms
No full textThis study presents an integrated methodology for evaluating operations and maintenance (O&M) costs for floating offshore wind turbines (FOWTs), incorporating vessel motion dynamics. By combining UWiSE, a discrete-event simulation tool, with SafeTrans, a voyage simulation software, vessel motion effects during offshore operations are modeled. The approach is demonstrated in a case study at two wind farm sites, Marram Wind and Celtic Sea C. Three major component replacement (MCR) strategies were assessed: Tow-to-Port (T2P), Floating-to-Floating (FTF), and Self-Hoisting Crane (SHC). The T2P strategy yielded the highest O&M costs—94 kEUR/MW/year at Marram Wind and 97 kEUR/MW/year at Celtic Sea C—due to the extended MCR durations (90–180 days), leading to lower availability (90–94%). In contrast, the FTF and SHC strategies offered significantly lower costs and downtime. The SHC strategy was most cost-effective, reducing costs by up to 64% while achieving 97–98% availability. The integrated approach was found to be either more restrictive or more permissive depending on the specific sea states influencing the motion responses. This variability highlights the critical role of motion-based dynamics in promoting safe and efficient O&M practices, particularly for advancing FOWT operations
The evolution of the digital service ecosystem and digital business model innovation in retail : The emergence of meta-ecosystems and the value of physical interactions
No full textAs e-commerce has increasingly gained traction in the retail market, many traditional “brick-and-mortar” retailers are innovating their business models and making the transition towards digital business models. While scholars have started to examine the influence of digitalization on various business model elements, they have so far paid little attention to its implications on the external relationships in which firms engage for value creation. Building on a qualitative analysis of seventeen interviews, this study develops a two-stage framework for the transition to digital business models. In Stage 1, retailers collaborate with specialized service providers to implement a digital business model. As firms from the retail ecosystem collaborate with firms from the digital-service ecosystem to create a value proposition for end-customers, a meta-ecosystem emerges. In Stage 2, firms (retailers) seek to differentiate themselves from their competitors in the meta-ecosystem. Physical interactions with the digital service providers, the product suppliers, and the customers are a primary means towards this end. Thus, digitalization does not make physical interactions and close personal ties obsolete. Our study has substantial implications for the academic literature and management practice.© 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed
Value logics for service innovation : practice-driven implications for service-dominant logic
No full textService-dominant logic (SDL) provides a conceptual understanding of and widens the view on value creation in service innovation for product-centric companies. However, empirical research linking SDL and service innovation is still limited albeit expanding. This study provides insights beyond existing discussions on product and service dimensions using the theoretical lens of the value logic perspective. More specifically, the purpose of this study is to examine how value can be understood, targeted, and created in the pursuit of service innovation by product-centric manufacturing companies. Building on a previous investigation of two multinational product-centric manufacturing companies, this paper identifies and develops a theoretical model to describe the space shift in service innovation with four different kinds of value logics, namely, product-based value logic, service-based value logic, virtual-based value logic, and systemic-based value logic. Using a digitalization-driven new service innovation, namely the My Control System, which is a web-based service delivery platform, this paper describes space shifts to enhance value through four value logics as efforts. Further, challenges associated with different value logics are described in terms of complexity traps and service gaps. The study also contributes to bridging the gap between SDL theory and practice by developing a midrange theoretical model for value creation as a specification and amendment to SDL that supports SDL-guided service innovation and servitization in practice. © 2018 The Author(s
HARMONISED LCA FOR WIND POWER: Environmental profiles of electricity generation from wind energy: Aims and needs for harmonised life cycle assessment
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