A5031304583- Wind Energy Research and Development
- Wind and Air Flow Studies
- Advanced Statistical Methods and Models
- Fluid Dynamics and Vibration Analysis
- Statistical Methods and Inference
- Optimal Experimental Design Methods
- Bayesian Methods and Mixture Models
- Energy Load and Power Forecasting
- Fluid Dynamics and Turbulent Flows
- Aerodynamics and Fluid Dynamics Research
- Wind Turbine Control Systems
- Statistical Distribution Estimation and Applications
- Advanced Statistical Process Monitoring
- Statistical Methods in Clinical Trials
- Dutch Social and Cultural Studies
- Statistical Methods and Bayesian Inference
- Multi-Criteria Decision Making
- Meteorological Phenomena and Simulations
- Plant Water Relations and Carbon Dynamics
- Fuzzy Systems and Optimization
- Research in Social Sciences
- Ocean Waves and Remote Sensing
- Forest Management and Policy
- Probabilistic and Robust Engineering Design
- demographic modeling and climate adaptation
Technical University of Denmark
2015-2024
The Netherlands Cancer Institute
2023
National Renewable Energy Laboratory
2021
Eindhoven University of Technology
1994-2014
Centraal Bureau voor de Statistiek
1985-2013
Southeastern University
2009
Durham University
1996-2004
Shell (Netherlands)
1998
University of Alabama
1997
Graduate School Experimental Plant Sciences
1981-1990
We present an overview of the literature on nonparametric or distribution-free control charts for univariate variables data. highlight various advantages these while pointing out some disadvantages more traditional, distribution-based charts. Specific observations are made in course review articles and constructive criticism is offered so that opportunities further research can be identified. Connections to areas active made, such as sequential analysis, relevant process control. hope this...
Abstract An improved k ‐ ϵ turbulence model is developed and applied to a single wind turbine wake in neutral atmospheric boundary layer using Reynolds averaged Navier–Stokes solver. The proposed includes flow‐dependent C μ that sensitive high velocity gradients, e.g., at the edge of wake. modified compared with original eddy viscosity model, Large‐Eddy Simulations field measurements eight test cases. comparison shows deficits, predicted by are much closer ones calculated Simulation those...
ABSTRACT Wind turbine wake can be studied in computational fluid dynamics with the use of permeable body forces (e.g. actuator disc, line and surface). This paper presents a general flexible method to redistribute wind blade as domain. The take any kind shape discretization, determine intersectional elements grid size these proportionally forces. potentially reduce need for mesh refinement region surrounding rotor and, therefore, also cost large farm simulations. special case disc is...
Abstract Previous research has revealed the need for a validation study that considers several wake quantities and code types so decisions on trade‐off between accuracy computational cost can be well informed appropriate to intended application. In addition guiding choice setup, rigorous model exercises are needed identify weaknesses strengths of specific models guide future improvements. Here, we consider 13 approaches simulating wakes observed with nacelle‐mounted lidar at Scaled Wind...
We present a methodology to process wind turbine wake simulations, which are closely related the nature of observations and processing these generate so-called cases. The method involves averaging large number simulations over range directions partly accounts for uncertainty in direction assuming that same follows Gaussian distribution. Simulations single double measurements at Sexbierum onshore farm performed using fast engineering model based on Jensen model, linearized computational fluid...
Abstract. Numerical wind resource modelling across scales from the mesoscale to turbine scale is of increasing interest due expansion offshore energy. Offshore farm wakes can last several tens kilometres downstream and thus affect resources a large area. So far, scale-specific models have been developed but it remains unclear how well different model types represent intra-farm wakes, farm-to-farm as wake recovery behind farm. Thus, in present analysis simulation set complexity, fidelity,...
Abstract. Numerical simulations of the Vestas multi-rotor demonstrator (4R-V29) are compared with field measurements power performance and remote sensing wake deficit from a short-range WindScanner lidar system. The predict gain 0 %–2 % in due to rotor interaction at below rated wind speeds. curve also show that increases speed by 1.8 %, which can result 1.5 increase annual energy production. numerical four distinct deficits near wake, merge into single-wake structure further downstream....
The recently developed k-ε-fP eddy-viscosity model is applied to one on-shore and two off-shore wind farms.The results are compared with power measurements of the standard k-ε model.In addition, direction uncertainty used correct a Gaussian filter.The underpredicts deficit first downstream turbines, whereas eddyviscosity shows good agreement measurements.However, difference in predicted by turbulence models becomes smaller for turbines that located further downstream.Moreover, between...
The newly developed k-ε-fP eddy viscosity model is applied to double wind turbine wake configurations in a neutral atmospheric boundary layer, using Reynolds averaged Navier-Stokes solver.The turbines are represented by actuator disks.A proposed variable disk force method employed estimate the power production of interacting and results compared with two existing methods; based on tabulated airfoil data axial induction from 1D momentem theory.The calculates correct power, while other methods...
Abstract. The interaction between the Coriolis force and a wind farm wake is investigated by Reynolds-averaged Navier–Stokes simulations, using two different representations: high roughness 5 × actuator disks. Surprisingly, calculated deflection opposite in simulations. A momentum balance cross flow direction shows that disks complex due to turbulent mixing of veered from above into farm, which not observed for change. When simulations are performed with horizontally constant order isolate...
Abstract. Offshore wind farms are more commonly installed in farm clusters, where interaction can lead to energy losses; hence, there is a need for numerical models that properly simulate interaction. This work proposes Reynolds-averaged Navier–Stokes (RANS) method efficiently the effect of neighboring on power and annual production. First, novel steady-state atmospheric inflow proposed tested application RANS simulations large farms. Second, RANS-based parameterization introduced, actuator...
Abstract. Wind turbines in an offshore wind farm typically have the same hub height, and this case, power of a could be predicted if flow field horizontal 2D plane at height is accurately. Nevertheless, Reynolds-averaged Navier-Stokes (RANS) simulations flows are predominantly made full 3D domains, which naturally more computationally expensive than simulations. In work, systematic comparison between RANS various configurations to assess differences computational cost accuracy. For our...
Summary In this paper the concept of ‘rank‐interaction’ is introduced and a distribution‐free method for testing against presence suggested in case two‐way layout (classification) with m (> 1) observations per cell. Roughly speaking rank‐interaction can be understood as phenomenon at which ranks levels some relevant variable are different classes other factor. The exact null distribution test statistic has been computed cases. asymptotic under hypothesis derived. A by J.V. B radley his...
SCADA data, recorded on the downstream wind farm, has been used to identify flow cases with visible clustering effects. The inflow condition is derived from a partly undisturbed turbine, due lack of mast measurements. data analysis concludes that centre deficit for farm disturbed distinct maximum zone located only 5-10D entrance. This zone, representing 20-30% speed reduction, increases and moves increasing cluster effect not outside sector 20-30°. eight models represented in this benchmark...
Abstract A new k ‐ ϵ model is introduced that consistent with Monin–Obukhov similarity theory (MOST). The proposed compared another was developed in an attempt to maintain inlet profiles compatible MOST. It shown the previous not MOST for unstable conditions, while can over distances of 50km. Copyright © 2016 John Wiley & Sons, Ltd.
This article describes Computational Fluid Dynamics (CFD) simulations of flows in a wind farm complex terrain Shaanxi, China and the comparisons computational results with utility scale field measurements. The CFD performed study are using either Reynolds-Averaged Navier–Stokes (RANS) or Large-Eddy Simulation (LES) solver. RANS method together an Actuator Disc (AD) approach is employed to predict performance 25 turbines farm, while LES Line (AL) technique used obtain detailed description...
Abstract. The design of wind turbines and farms can be improved by increasing the accuracy inflow models representing atmospheric boundary layer. In this work we employ one-dimensional Reynolds-averaged Navier–Stokes (RANS) simulations idealized layer (ABL), using turbulence closures with a length-scale limiter. These represent mean effects surface roughness, Coriolis force, limited ABL depth, neutral stable conditions four input parameters: roughness length, parameter, maximum geostrophic...
A Reynolds-averaged Navier-Stokes code is used to simulate the interaction of two neighboring wind farms. The influence Coriolis force investigated by modeling atmospheric surface/boundary layer with three different methodologies. results show that negligible for a single turbine, small farm, but important simulations farm wake interaction.
The turbulence time and length scales of a single wind turbine wake subjected to atmospheric are calculated from two large eddy simulations that differ in ambient intensity. smallest scale the is about half rotor radius it increases for higher levels. compared with Reynolds-averaged Navier-Stokes employing standard three extended k-ε models: k-ε-fP model van der Laan, Shih Durbin. It shown all models can be written similar form. All based predict comparable simulations. underpredicts...
Abstract. Understanding wind turbine wake recovery is important for developing models of interaction employed in the design energy-efficient farm layouts. Wake often assumed or explained to be a shear-driven process; however, this generally not accurate. In work we show that wakes recover mainly due divergence (lateral and vertical gradients) Reynolds shear stresses, which transport momentum from freestream towards center. The mechanisms are illustrated using simple analytic model results...