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Reduction of spillover effects on independent modal space control through optimal placement of sensors and actuators
Full text linkWind tunnel tests on floating offshore wind turbines: a proposal for Hardware-In-the-Loop approach
No full textThis paper reports the realization of a 2-DoF experimental rig, performed at Politecnico di Milano Wind Tunnel, aimed at simulating the motion of a floating wind turbine scale model, due to combined effect of hydrodynamic and aerodynamic loads. As floating offshore wind farms are becoming objects of interest among the international scientific community, experimental tests have been increasingly demanded to support dynamic and structural numerical simulations. Furthermore measurements on real prototypes are very complex and expensive and it is difficult to use these data to validate prediction models because of the uncertainties in the definitions of the environmental data, such as sea state and incoming wind. The motivation of this project is to provide an experimental set-up working in a fully controlled test environment (with measurable input/output) in order to validate numerical codes. The paper reports the features of the experimental rig, the results coming from the validation tests on the rig, through a dedicated “off-line” experimental campaign and, conclusively, a proposal for a “Hardware-In-The-Loop” real time functioning mode
Multi-Objective Design Of a High-Performance Active Pitch-Controlled H-Darrieus VAWT For Urban Installation
No full text
An experimental test rig to simulate hydrodynamic forcing on floating offshore wind turbine platforms, OWEMES, Offshore Wind and Other Marine Renewable Energies in Mediterranean and European Seas, 5-7 sep 2012, Roma
No full textWind tunnel tests on floating offshore wind turbines: a proposal for Hardware-in-the-Loop approach to validate numerical codes
No full textThis paper describes the realization of a 2-DoF experimental rig, performed at Politecnico di Milano Wind Tunnel, aimed at simulating the motion of a floating wind turbine scale model, due to combined effect of hydrodynamic and aerodynamic loads. As floating offshore wind farms are becoming objects of interest among the international scientific community, experimental tests have been increasingly demanded to support dynamic and structural numerical simulations. Furthermore measurements on real prototypes are very complex and expensive and it is difficult to use these data to validate prediction models because of the uncertainties in the definition of the environmental data, such as sea state and incoming wind. The motivation of this project is to provide an experimental set-up working in a fully controlled test environment (with measurable input/output) in order to validate numerical codes. The paper describes the features of the experimental rig, the results coming from the validation tests on the rig, through a dedicated "off-line" experimental campaign and, conclusively, a proposal for a "Hardware-In-The-Loop" real time functioning mode
Wind tunnel validation of AeroDyn within LIFES50+ project: Imposed Surge and Pitch tests
Full text linkThis paper presents the first set of results of the steady and unsteady wind tunnel tests, performed at Politecnico di Milano wind tunnel, on a 1/75 rigid scale model of the DTU 10 MW wind turbine, within the LIFES50+ project. The aim of these tests is the validation of the open source code AeroDyn developed at NREL. Numerical and experimental steady results are compared in terms of thrust and torque coefficients, showing good agreement, as well as for unsteady measurements gathered with a 2 degree-of-freedom test rig, capable of imposing the displacements at the base of the model, and providing the surge and pitch motion of the floating offshore wind turbine (FOWT) scale model. The measurements of the unsteady test configuration are compared with AeroDyn/Dynin module results, implementing the generalized dynamic wake (GDW) model. Numerical and experimental comparison showed similar behaviours in terms of non linear hysteresis, however some discrepancies are herein reported and need further data analysis and interpretations about the aerodynamic integral quantities, with a special attention to the physics of the unsteady phenomenon
Design and realisation of a high-performance active pitch-controlled H-Darrieus VAWT for urban installations
No full textStudy of the Effect of Water Depth on Potential Flow Solution of the OC4 Semisubmersible Floating Offshore Wind Turbine
Full text linkAbstractThis work aims at assessing the influence of water depth on the potential flow solution for a semisubersible floating offshore wind turbine. More specifically, the system developed for the Offshore Code Comparison Collaboration Continuation (OC4) of the Inter- national Energy Agency IEA was considered for this paper. This work has been inspired by previous studies concerning the effect of shallow water on Liquified Natural Gas Carriers (LNGC). The influence of water depth on the hydrodynamics of such systems is evident from measurements as well as from simulations, specifically when secondary effects in the wave and flow modelling are addressed. This scenario has motivated the comparative study for the Floating Wind Turbine herein reported, also taking into account second order hydrodynamics (Quadratic Transfer Functions, QTF) as well as low frequency contribution in the incoming wave, due to shallow water (Setdown effect). The simulations were conducted relying on the codes DIFFRAC and aNySIM, de- veloped at Maritime Research Institute of Netherlands (MARIN) and the results are presented for a range of water depth between the nominal value of 200 m and the extreme shallow water of 30 m
Aerodynamic design methodology for wind tunnel tests of wind turbine rotors
Full text linkThis paper illustrates the methodology and the experimental verification of the design of a 1/75 aero-elastic scaled rotor of the DTU 10 MW reference wind turbine for wind tunnel tests. The aerodynamic design was focused on the minimization of the difference, in terms of thrust coefficient, with respect to the full scale reference. From the Selig low-Reynolds airfoils database, the SD7032 one was chosen for this purpose and a corresponding constant section wing was tested at DTU red wind tunnel, providing force and distributed pressure coefficients for the design, in the Reynolds range 30−250×103 and for different angles of attack. The aero-elastic design algorithm was set to define the optimal spanwise thickness over chord ratio (t/c), the chord length and the twist, in order to match at least the first flapwise scaled natural frequency. An aluminium mould for the carbon fibre autoclave process was CNC manufactured based on B-Splines CAD definition of the external geometry given as an output of the design procedure. Wind tunnel tests at were carried out Politecnico di Milano on the whole 1/75 wind turbine scale model, confirming the successful aerodynamic design and manufacturing approaches. The experimental modal analysis carried out to verify the structural consistency of the scaled blade is also reported
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