Search results for "edge"
showing 10 items of 3866 documents
Comparison of numerical modelling techniques for impact investigation on a wind turbine blade
2019
Wind turbine blades are exposed to numerous impact risks throughout their lifetimes. The impact risks range from bird collisions during operation to impacts with surrounding structures at the time of transportation and installation. Impact loads on the fibre composite blades can induce several complex, simultaneously interacting and visually undetectable damage modes and have a high potential to reduce the local and global blade stiffness. An assessment of such impact-induced damages is therefore necessary and usually involves high computational costs using numerical procedures, especially when analysing large composite components. To minimise this computational expense, different numerical…
Minimum Leading Edge Protection Application Length to Combat Rain-Induced Erosion of Wind Turbine Blades
2021
Leading edge erosion (LEE) repairs of wind turbine blades (WTBs) involve infield application of leading edge protection (LEP) solutions. The industry is currently aiming to use factory based LEP coatings that can applied to the WTBs before they are shipped out for installation. However, one of the main challenges related to these solutions is the choice of a minimum LEP application length to be applied in the spanwise direction of the WTBs. Generally, coating suppliers apply 10–20 m of LEP onto the blades starting from the tip of the blade using the “rule of thumb”, and no studies in the literature exist that stipulate how these LEP lengths can be calculated. In this study, we extend the sc…
Effects of Onshore and Offshore Environmental Parameters on the Leading Edge Erosion of Wind Turbine Blades: A Comparative Study
2021
Abstract The presence of rain-induced leading edge erosion of wind turbine blades (WTBs) necessitates the development of erosion models. One of the essential parameters for erosion modeling is the relative impact velocity between rain droplets and the rotating blade. Based on this parameter, the erosion damage rate of a WTB is calculated to estimate the expected leading edge lifetime. The environmental conditions that govern this parameter have site-specific variations, and thus, rain and wind loading on a turbine differ for onshore and offshore locations. In addition, there are wave loads present in the offshore environment. The present paper tries to provide guidelines for erosion modelin…
Numerical investigation of rain droplet impact on offshore wind turbine blades under different rainfall conditions: A parametric study
2020
The leading edge of a fiber composite wind turbine blade (WTB) is prone to erosion damages due to repeated rain droplet impact during its service life. Such damages are critical to the blade's aerodynamic as well as structural performance, ultimately resulting in substantial repair costs. An effective design of a coating material for WTB is necessary and its analysis must include variables associated with erosive rain droplets such as (1) droplet diameter, (2) impact velocity, and (3) droplet impact angle. The present paper develops and validates a coupled fluid structure interaction (FSI) computational model for simulating rain droplet impact on WTBs, where the structure domain is modelled…
Poleward range expansion without a southern contraction in the ground beetle Agonum viridicupreum (Coleoptera, Carabidae)
2011
We investigated the extent of poleward shifts in the distribution range of Agonum viridicupreum due to climate change in the western Palaearctic. Species' records were obtained from extensive literature sources as well as from collections, and consistent amateur entomologists' recordings. Within the general geographic range of the species, we analyzed in detail two parts of both, the northern and southern distribution range boundaries: (1 and 2) north-western Germany (leading or high-latitude edge), (3) Israel and (4) southern Italy (rear or low-latitude edge). Temporal changes in the occurrence data of the species indicated a northward shift of the leading edge of a minimum of 100 km withi…
Leading Edge Erosion of Wind Turbine Blades: Effects of Environmental Parameters on Impact Velocities and Erosion Damage Rate
2021
Abstract Leading edge erosion (LEE) of a wind turbine blade (WTB) is a complex phenomenon that contributes to high operation and maintenance costs. The impact between rain droplets and rotating blades exerts cyclic fatigue stresses on the leading edge — causing progressive material loss and reduced aerodynamic performance. One of the most important parameters for erosion modelling and damage prediction is the relative impact velocity between rain droplets and rotating blade and depends upon the environmental conditions. The environmental condition, in general, could vary for onshore and offshore wind turbines (OWTs) — for instance, the presence of wave-induced loads along with less turbulen…
The emergence of lean construction in the Norwegian AEC industry
2021
Lean construction has inspired the AEC industry globally over the last decades, and this manifests within a wide array of contexts. The purpose of this paper is to provide a narrative-based qualitative analysis of the emergence and impact of Lean construction on a national level, notably in the Norwegian AEC industry. The analysis is based on the concept of paradigm shift and on empirical knowledge in the form of narratives. The narratives of practitioners and researchers provide deep insights into how Lean Construction has inspired the Norwegian AEC industry and academia, respectively. The reflections indicate that the introduction of the Lean construction principles and tools in the Norwe…
Do teaching innovation projects make a difference? Assessing the impact of small-scale funding
2018
This article presents the outcomes of a research study carried out during 2015–2016 at the University of Valencia (Spain) to understand the factors influencing the impact of small-scale innovation funding on teachers’ practices, the learning culture of the teaching team and the satisfaction of students’ learning. The research used a mixed-method design: a questionnaire examined the factors influencing transfer of innovation; in-depth interviews with project leaders yielded information about the adoption and transfer of funded projects; and a focus group with institutional managers provided suggestions to improve the efficiency of the innovation projects and calls. The results provide qualit…
Combining Resources: A Participatory Intervention Promoting Organisational Learning, Social Innovation and Interorganisational Collaborations In Crim…
2020
This chapter presents a participatory model for promoting organisational learning and innovation with potential application in criminal justice related organisations. We share the sensemaking process engaged in by the COLAB consortium tasked with comparing and contrasting a range of participatory interventions and developing a potentially hybrid model that combined the strengths of each. We describe this model on 11 key dimensions, that in themselves offer a useful tool through which different participatory methods might be compared. An expanded participatory model based on the Change Laboratory model and expansive learning cycle is presented, one augmented with the beneficial components of…
Communicating interculturality in the world of work
2015
Lectio praecursoria puheviestinnän väitöskirjaksi tarkoitetun tutkimuksen Communicating interculturality in the workplace tarkastustilaisuudessa Jyväskylän yliopistossa 24.10.2015. Vastaväittäjänä toimi professori Fred Dervin (Helsingin yliopisto) ja kustoksena professori Maarit Valo.