A large-scale wind turbine model installed on a floating structure:experimental validation of the numerical design

In the field of floating wind energy, large-scale wind turbine models deployed in natural environments represent a key link between small-scale laboratory tests and full-scale prototypes. While implying smaller cost, design and installation effort than a full-scale prototype, large-scale models are technologically very similar to prototypes, can be tested in natural sea and wind conditions, and reduce by a consistent amount the dimensional scaling issues arising in small-scale experiments. In this framework the presented work report the aerodynamic and control system assessment of a 1:15 model of the DTU 10 MW wind turbine installed on a multipurpose-platform model for fish farming and energy production. The model has operated for 6 months in a natural laboratory and has been exposed to fully natural and uncontrolled environmental conditions. Assessment is performed in terms of rotor thrust force and power controller parameters such as rotor speed, blade pitch and rotor power as a function of incoming wind speed

Adding aerodynamic damping: the wing design for the Third Bosphorus Bridge

This paper is about the design of wing profiles adequate for giving to the Third Bosphorus Brige an additional aerodynamic damping on both vertical bending as well as torsional modes. The additional damping estimate procedure is made through a simplified quasi steady approach. A CFD approach has been used for a preliminary design and optimization of the wing profile and its position over the wind screen at the upwind and downwind location

Assessing the impact of waves and platform dynamics on floating wind-turbine energy production

Waves have the potential to increase the power output of a floating wind turbine by forcing its rotor to move against the wind. Starting from this observation, we use four multi-physics models of increasing complexity to investigate the role of waves and platform movements in the energy conversion process of four floating wind turbines of 5–15 MW in the Mediterranean Sea. Progressively adding realism to our simulations, we show that large along-wind rotor movements are needed to increase the power output of a floating wind turbine; however, these are prevented by the current technology of spar and semi-submersible platforms. Wind turbulence is the main cause of power fluctuations for the four floating wind turbines we examined and is preponderant over the effect of platform motions due to waves. In a realistic met-ocean environment, the power curve of the floating wind turbines we studied is lower than that obtained with a fixed foundation, with reductions in the annual energy production of 1.5 %–2.5 %. The lower energy production is mainly ascribed to the platform mean tilt, which reduces the rotor's effective area.</p

Development and validation of a coupled numerical model for offshore floating multi-purpose platforms

A multi-purpose platform (MPP) is an offshore system designed to serve the purposes of more than one off-shore industry. Over the past decades, a number of industries have expanded or are expanding, from onshore to offshore locations. In the present work, the MPP proposed in the framework of Blue Growth Farm project is considered. The aim here is to develop and validate a coupled aero-hydro-servo-elastic numerical model, which will be used to predict the dynamic response of the MPP under a wide range of environmental condi-tions. Model test research was conducted to validate the developed numerical model. The model test was carried out in the water basin at Centrale Nantes, employing the Froude scale strategy. An innovative ap-proach to modelling wind load in the experimental environment was proposed and applied. This paper re-ports the up-to-date research outcome of the Blue Growth Farm project - numerical model development and validation

New engineering approach for the development and demonstration of a multi-purpose platform for the Blue Growth Economy

Aquaculture is currently the fastest growing food sector in the world and the open oceans are seen as one of the most likely areas for large scale expansion [1], [2], [3]. The global demand for seafood is continuing to rise sharply, driven by both population growth and increased per capita consumption, whilst wild capture fisheries are constrained in their potential to produce more seafood. A recently funded EC project, the Blue Growth Farm BGF (GA n. 774426, 1st June 2018 ÷ 30th September 2021) aims at contributing to this world need with an original solution. The Blue Growth Farm proposes an efficient, cost competitive and environmentally friendly multi purpose offshore farm concept based on a modular floating structure, moored to the seabed, meeting requirements of efficiency, cost-competitiveness and environmental friendless, where automated aquaculture and renewable energy production systems are integrated and engineered for profitable applications in the open sea. In the present paper, the overall engineering approach developed to carry out the research work is presented, described and justified. Different technical and scientific challenges are addressed through an integrated industrial engineering design approach, where all disciplines are tuned to achieve the Blue Growth Farm main targets, represented by: i) guaranteeing expected nominal fish production thanks to advanced automation and remote control capabilities; ii) minimizing the pollution introduced at marine ecosystem level when exploiting the marine natural resources, whilst increasing the social acceptance and users community agreement; iii) maximizing the electricity production in the Blue Growth Farm potential installation area ecosystem to provide energy supply to the on board electrical equipment and to dispatch the extra produced electric energy to the land network. Preliminary engineering design results are promising to demonstrate effective increase of safety and efficiency by reducing on board human effort and consequently risks at offshore, thus to make commercial scale open ocean farming a reality

Mother-to-child transmission of human immunodeficiency virus in Italy : temporal trends and determinants of infection

In order to analyse temporal trends in vertical transmission rates of human immunodeficiency virus (HIV) and determinant of congenital HIV infection in Italy, we have considered data from a network of hospitals co-operating in the Italian Collaborative Study on HIV infection in pregnancy, conducted between 1988 and 1995. A total of 1040 women entered the study. The HIV-1 status of the babies was known in 848 cases (81.5%). Transmission rates were highest in the period 1988\u20131991, then tended to decrease and in 1995 the rate was 9.7 per 100 children (this finding, however, was based on only six infected children and the trend was not statistically significant). Considering the overall series, the risk of vertical HIV transmission was higher in women with low CD4 count in pregnancy [odds ratio (OR) <400 versus \u2a7e400 1.8, 95% confidence interval (CI) 1.1\u20132.9]. In comparison with vaginal delivery the risk of transmission was 0.3 (95% CI 0.1\u20130.5) and 0.6 (95% CI 0.3\u20131.2) respectively for elective and emergency delivery. In comparison with women who delivered at term (\u2a7e37 gestation weeks) the OR of HIV infection of the babies for the whole series was 2.2 (95% CI 1.3\u20133.6) in women who delivered preterm. Similar findings emerged when the analysis was conducted considering, separately, subjects observed in the period 1988\u20131991 and 1992\u20131995. The frequency of Caesarean section increased from 26.5% of deliveries in 1988\u20131991 to 36.2% in 1992\u20131995. Consequently, most temporal differences disappeared after standardization for mode of delivery, but the rate in 1995 was still lower than in 1988\u20131994