A5009119669- Wind Energy Research and Development
- Fluid Dynamics and Vibration Analysis
- Wind and Air Flow Studies
- Wave and Wind Energy Systems
- Fluid Dynamics and Turbulent Flows
- Lattice Boltzmann Simulation Studies
- Fluid Dynamics Simulations and Interactions
- Aerospace Engineering and Energy Systems
- Aerodynamics and Fluid Dynamics Research
- Structural Health Monitoring Techniques
- Coastal and Marine Dynamics
- Vibration and Dynamic Analysis
- Computational Fluid Dynamics and Aerodynamics
- Biomimetic flight and propulsion mechanisms
- Model Reduction and Neural Networks
- Marine and Offshore Engineering Studies
- Turbomachinery Performance and Optimization
- Probabilistic and Robust Engineering Design
- Spacecraft Dynamics and Control
- Ship Hydrodynamics and Maneuverability
- Offshore Engineering and Technologies
- Flow Measurement and Analysis
- Ocean Waves and Remote Sensing
- Structural Analysis and Optimization
- Tropical and Extratropical Cyclones Research
Delft University of Technology
2016-2025
Imperial College London
2012-2014
Université Libre de Bruxelles
2008-2010
Vortex generators (VGs) have proven their capabilities in wind turbine applications to delay stall steady flow conditions. However, behaviour unsteady conditions is insufficiently understood. This paper presents an experimental study that demonstrates the effect of VGs flow, including controlling and suppressing dynamic process. An airfoil, particularly designed for a vertical-axis turbine, has been tested tunnel caused by sinusoidal pitching motion. The pressure distributions, lift, drag...
Wind farms experience significant efficiency losses due to the aerodynamic interaction between turbines. A possible control technique minimize these is yaw-based wake steering. This paper investigates potential for improved performance of Lillgrund wind farm through a detailed calibration low-fidelity engineering model aimed specifically at The importance each parameter assessed sensitivity analysis. work shows that overparameterized as least one can be excluded from calibration. calibrated...
Currently, the design of floating offshore wind systems is primarily based on mid-fidelity models with empirical drag forces. The tuning model coefficients requires data from either experiments or high-fidelity simulations. As part OC6 (Offshore Code Comparison Collaboration, Continued, Correlation, and unCertainty (OC6) a project under International Energy Agency Wind Task 30 framework) project, present investigation explores latter option. A verification validation study computational...
Abstract. Wind turbine wakes can be treated as a complex system of helical vortices. When this destabilizes, the wake recovers its velocity deficit through mixing and entertainment energy from surrounding flow. How fast effectively that happens depends on inflow characteristics also influenced by how turbines are operated. Dynamic induction control techniques such helix affect onset instability transition near to far wake, but exact mechanisms still unclear. Its potential in wind farm...
Abstract. Floating offshore wind turbines experience complex hydrodynamic and aerodynamic loading influenced by substructure types stochastic environmental conditions. Accurately estimating the lifetime fatigue loads requires analyzing thousands of operational scenarios, leading to high computational costs. Moreover, choosing right input features driving in floating systems appropriately binning them still remains an open question. We present a fast probabilistic surrogate that maps site...
Abstract. A laboratory-scale model of the DTU 10 MW wind turbine is investigated under prescribed surge, sway, roll, pitch, yaw and coupled surge-pitch motions using YALES2, a high-fidelity large-eddy simulation (LES) tool to an actuator-line model. The are sinusoidal two cases per degree-of-freedom (DOF) considered: one with low Strouhal number St high normalized amplitude A*, vice versa. operated in vicinity rated conditions, constant rotor speed steady uniform free-stream velocity....
The rotor of floating offshore wind turbines with platform motions may undergo different working states during its operation, e.g. from windmill state to vortex ring and propeller state. In this paper, an aerodynamic model based on a free wake method is used simulate the undergoing surge motion. associated change evaluated quantitatively visually. results show that full cycle motion platform, experiences alternative onset state, while later two occur only downwind rotor. load corresponding...
Abstract. Floating offshore wind turbines may experience large surge motions, which can cause blade–vortex interaction if they are similar to or faster than the local speed. Previous research hypothesized that this phenomenon represented a turbulent wake state even vortex ring state, rendering actuator disc momentum theory and blade element invalid. This hypothesis is challenged, we show valid accurate in predicting induction at surge, for fast motions. To accomplish this, develop dynamic...
Embedding tidal turbines within simulations of realistic large-scale flows is a highly multi-scale problem that poses significant computational challenges. Here this tackled using actuator disc momentum (ADM) theory and Reynolds-averaged Navier–Stokes (RANS) with, for the first time, dynamically adaptive mesh optimisation techniques. Both k−ω SST RANS models have been developed Fluidity framework, an CFD solver, model validated against two sets experimental flume test results. A brief...
We present a computational fluid dynamic analysis of boundary layer transition on leading edge inflatable kite airfoils used for airborne wind energy generation. Because the operation in pumping cycles, airfoil is generally subject to wide range Reynolds numbers. The based combination shear stress transport turbulence model with γ-R˜eθt model, which can handle laminar and its turbulence. implementation both models OpenFOAM described. show validation method sailwing (ie, wing membrane) an...
Abstract. This study reports the results of second round analyses Offshore Code Comparison, Collaboration, Continued, with Correlation and unCertainty (OC6) project Phase III. While first investigated rotor aerodynamic loading, here, focus is given to wake behavior a floating wind turbine under large motion. Wind tunnel experimental data from UNsteady Aerodynamics for FLOating (UNAFLOW) are compared simulations provided by participants methods codes different levels fidelity. The effect...
Abstract. This study reports the results of second round analyses OC6 project Phase III. While first investigated rotor aerodynamic loading, here focus is given to wake behavior a floating wind turbine under large motion. Wind tunnel experimental data from UNsteady Aerodynamics for FLOating (UNAFLOW) are compared with simulations provided by participants methods and codes different levels fidelity. The effect platform motion both on near far investigated. More specifically, tip vortices in...
Abstract. The rotor of a floating wind turbine is subject to complex aerodynamics due changes in relative speeds at the blades and potential local interactions between blade sections near wake. These are not yet fully understood. Lab-scale experiments highly relevant for capturing these phenomena provide means validation numerical design tools. This paper presents new tunnel experimental setup able study aerodynamic response when subjected prescribed motions. present uses 1:148 scale model...
Abstract Actuator line modeling of wind turbines requires the definition a free‐stream velocity in computational mesh and regularization kernel to project computed body forces onto domain. Both choices strongly influence results. In this work, novel sampling method—the so‐called effective model (EVM)—is implemented CFD software SOWFA, validated, compared pre‐existing approaches. Results show superior method robustness with respect width ( ) choice while preserving acceptable accuracy....
The state-of-the-art in wind-farm flow-physics modeling is Large Eddy Simulation (LES) which makes accurate predictions of most relevant physics, but requires extensive computational resources. next-fidelity model types are Reynolds-Averaged Navier–Stokes (RANS) two orders magnitude cheaper, resolve only mean quantities and the effect turbulence. They often fail to accurately predict key effects, such as wake recovery rate. Custom RANS closures designed for wakes exist, so far do not...
A modified free-wake vortex ring model is proposed to compute the dynamics of a floating horizontal-axis wind turbine, which divided into two parts. The near wake uses blade bound and trailed model, developed based on filament method with straight lifting lines assumption. By contrast, far method. good compromise between accuracy computational cost, for example when compared more complex methods. present used assess influence platform motions performance turbine rotor. results are validated...
Abstract. Floating Offshore Wind Turbines may experience large surge motions which, when faster than the local wind speed, cause rotor-wake interaction. Previous research hypothesised that this phenomena can result in a turbulent wake state or even vortex ring state, invalidating Actuator Disc Momentum Theory and use of Blade Element Theory. We challenge hypothesis demonstrate is valid accurate predicting induction at actuator surge, for fast motions. To achieve this, we derive dynamic...
Abstract. Vortex-Induced Vibrations (VIV) of wind turbine towers during installation is an aero-structural problem significant practical relevance. may happen in the tower structure, especially when rotor-nacelle assembly not yet attached to or if rotor blades are connected tower-nacelle assembly. The complexity aeroelastic phenomena involved VIV makes modeling and analysis challenging. Therefore, aim current research investigate fundamental mechanisms causing onset sustenance vortex-induced...
Lorentz force velocimetry (LFV) is a contactless technique for the measurement of liquid metal flowrates. It consists measuring acting upon magnetic system and arising from interaction between an external field flow electrically conducting fluid. In this study, new design proposed so as to make independent fluid’s electrical conductivity. made one or two coils placed around circular pipe. The forces produced on each coil are recorded in time flows through highlighted that auto-...
The wind condition around floating offshore turbines (FOWTs) can be largely different from that developed bottom-mounted due to the platform motions. existing literature identifies four working state of FOWTs, one them being vortex ring (VRS) which may occur as rotor moves in its own wake. It is potentially a problem influences aerodynamic performance and lifetime FOWTs. still unclear when, what extent, does VRS happen turbines. aim this paper quantitatively predict occurrence during...
Abstract. Vortex-induced vibrations (VIVs) of wind turbine towers can be critical during the installation phase, when rotor–nacelle assembly is not yet mounted on tower. The present work uses numerical simulations to study VIVs a two-dimensional cylinder in transverse direction under flow conditions that are representative both from fluid dynamics and structural perspective. First, tools fluid–structure interaction algorithm validated by considering vibrating freely laminar flow. In case,...
The paper presents a novel method for numerically modelling fluid-structure interactions. consists of solving the fluid-dynamics equations on an extended domain, where computational mesh covers both fluid and solid structures. velocities are relaxed to one another through penalty force. latter acts thin shell surrounding Additionally, is represented domain by non-zero shell-concentration field, which obtained conservatively mapping onto mesh. outlines theory underpinning this method,...