Periodic Reporting for period 2 - zEPHYR (Towards a more efficient exploitation of on-shore and urban wind energy resources)
Periodo di rendicontazione: 2021-11-01 al 2023-10-31
The rise of a low-carbon society, compatible with economic growth and environmental sustainability, is pending on a number of technological evolutions and breakthroughs. In that line, the role played by wind energy is deemed to increase further in the next decades. The development of performant wind farms is pending upon the performance of each turbine composing the wind farm, and on the optimal harvesting of the local wind resources. A wind park performance is nowadays predicted assuming standard profiles of mean incoming velocity, turbulence intensities and scales, etc. corresponding to standard terrain topographies and atmospheric conditions. One main limitation of such standards is that the assumed flow and turbulence properties were established to fit databases gathered on a limited number of locations, which are by definition not representative of the various terrain configurations nor local micro-meteorological situations that can be met in practice. This is a concern for complex terrains and is furthermore hampering the implementation of wind turbines in urban environments, which constitutes nevertheless an important component of future environmentally-friendly Smart Cities thanks to the favourable local flow accelerations, pressure build-up, canyon effects, etc. offered by an urban canopy.
The ambition of this multi-disciplinary training platform was the development and application of advanced meso/microscale atmospheric models and the assessment of the impact of real terrain and local atmospheric effects on the predicted aerodynamic performance, structural dynamics and noise emissions, leading to a more efficient harvesting of wind energy resources in ‘conventional’ on-shore as well as urban environments through more accurate and robust simulation methodologies. Since human factors become a critical issue when considering implementing wind turbines in densely populated urban environments, zEPHYR also aimed to address the inter-dependencies between those factors (visual vs. acoustic effects, age or occupation, etc.) to better understand the motivations behind a community's endorsement or rejection of a new project.
The ambition of this multi-disciplinary training platform was the development and application of advanced meso/microscale atmospheric models and the assessment of the impact of real terrain and local atmospheric effects on the predicted aerodynamic performance, structural dynamics and noise emissions, leading to a more efficient harvesting of wind energy resources in ‘conventional’ on-shore as well as urban environments through more accurate and robust simulation methodologies. Since human factors become a critical issue when considering implementing wind turbines in densely populated urban environments, zEPHYR also aimed to address the inter-dependencies between those factors (visual vs. acoustic effects, age or occupation, etc.) to better understand the motivations behind a community's endorsement or rejection of a new project.
This multi-disciplinary training platform has brought together top-rank academia, research centres and industrial stakeholders, actively involved in top-level research in the fields of fluid dynamics, aeroacoustics, structural dynamics and fatigue life prediction, uncertainty quantification, optimization methods, system dynamics and control, and human factors. Several results have been achieved by the 15 Early-Stage Researchers involved in the project, including:
1) Development of simulation tools, such as software and workflows. These tools have been used to accurately assess the wind energy resources over complex terrains, predict the aerodynamic loads and the acoustic emissions, and simulate the noise propagation. Particular attention was given to complex rural terrains with large horizontal-axis wind turbines and urban areas with vertical-axis wind turbines.
2) Experimental campaigns to understand the noise generation mechanisms. The experimental campaigns focused on wind turbine blade sections to explain the physical phenomena responsible for the increased noise emissions that characterize wind turbines in a highly turbulent urban environment. The scope was to enhance noise predictions of low-order methods and propose noise mitigation strategies.
3) Numerical investigations of aerodynamic and aeroacoustic characteristics of wind turbines. Comparative studies between different wind turbine geometries, flow control strategies and optimized blade shapes have been performed by high-fidelity numerical simulations.
4) Understanding of societal barriers to the implementation of renewable (wind) energy projects. It suggested that the public acceptance concept has several limitations, as it is mainly focused on the relationship between the public and technology and the public and producer of technology. Science, Technology and Society perspectives such as socio-technical imaginaries, assemblage theory, and sustainability experiments can and have been applied to the analysis of socio-technical wind energy systems.
1) Development of simulation tools, such as software and workflows. These tools have been used to accurately assess the wind energy resources over complex terrains, predict the aerodynamic loads and the acoustic emissions, and simulate the noise propagation. Particular attention was given to complex rural terrains with large horizontal-axis wind turbines and urban areas with vertical-axis wind turbines.
2) Experimental campaigns to understand the noise generation mechanisms. The experimental campaigns focused on wind turbine blade sections to explain the physical phenomena responsible for the increased noise emissions that characterize wind turbines in a highly turbulent urban environment. The scope was to enhance noise predictions of low-order methods and propose noise mitigation strategies.
3) Numerical investigations of aerodynamic and aeroacoustic characteristics of wind turbines. Comparative studies between different wind turbine geometries, flow control strategies and optimized blade shapes have been performed by high-fidelity numerical simulations.
4) Understanding of societal barriers to the implementation of renewable (wind) energy projects. It suggested that the public acceptance concept has several limitations, as it is mainly focused on the relationship between the public and technology and the public and producer of technology. Science, Technology and Society perspectives such as socio-technical imaginaries, assemblage theory, and sustainability experiments can and have been applied to the analysis of socio-technical wind energy systems.
The zEPHYR project allowed the development of improved theories and new methodologies for the modelling of the atmospheric boundary layer, the aerodynamic performance of horizontal- and vertical-axis wind turbines, the acoustic emissions and the noise propagation. Furthermore, new measurement techniques have been proposed and applied to investigate the acoustic emissions of wind turbine blades.
These tools led to the creation of numerical models to predict wind turbine noise in complex urban environments that could be used by industries in the design and production of wind turbines. Other outcomes of the project have been the creation of a modelling tool for the automatic optimization of horizontal axes wind turbines and the development of a synthetic wind field generator for the analysis of wind turbines with a view to ensuring structure safety, optimal performance and minimal noise emissions.
These tools led to the creation of numerical models to predict wind turbine noise in complex urban environments that could be used by industries in the design and production of wind turbines. Other outcomes of the project have been the creation of a modelling tool for the automatic optimization of horizontal axes wind turbines and the development of a synthetic wind field generator for the analysis of wind turbines with a view to ensuring structure safety, optimal performance and minimal noise emissions.