Some modelling improvements for prediction of wind turbine rotor loads in turbulent wind
Author(s)
Muñoz-Simón, Arturo
Wynn, Andrew
Palacios, Rafael
Type
Journal Article
Abstract
This paper investigates the accuracy of three aerodynamic models to compute loads on wind turbine rotors under turbulent inflow: Blade Element Momentum (BEM); Unsteady Vortex Lattice
Method (UVLM) and Large Eddy Simulation with Actuator Line (LES-AL). Turbulent inflow conditions are numerically generated with a new approach that combines control of turbulence and
realistic velocity spectrum by using Mann boxes and LES simulations, respectively. Several deficiencies of the tested models are found and overcome through proposed improvements. First,
the BEM assumption of independent radial sections does not hold in turbulent cases with long
blades. Thus, a spatial filter to account for the interaction of radial sections in BEM is designed
through the analysis of these interactions with UVLM. Second, the absence of viscous drag in
UVLM is observed to lead to a very high rotor power coefficient, and it is shown that this can
be mitigated by including drag in UVLM with a BEM-like-approach through look-up tables. Third,
the free wake model in UVLM, required to accurately capture rotor thrust, significantly increases
computational cost. For this reason, a new wake discretisation scheme for the wake convection
equation in UVLM is proposed, in which a coarse discretisation is employed far from the solid
surfaces, which significantly reduces the computational time. Finally, these improvements and
the performance of the three fidelities are analysed in a reference 10 MW wind turbine rotor
demonstrating, in general, good agreement.
Method (UVLM) and Large Eddy Simulation with Actuator Line (LES-AL). Turbulent inflow conditions are numerically generated with a new approach that combines control of turbulence and
realistic velocity spectrum by using Mann boxes and LES simulations, respectively. Several deficiencies of the tested models are found and overcome through proposed improvements. First,
the BEM assumption of independent radial sections does not hold in turbulent cases with long
blades. Thus, a spatial filter to account for the interaction of radial sections in BEM is designed
through the analysis of these interactions with UVLM. Second, the absence of viscous drag in
UVLM is observed to lead to a very high rotor power coefficient, and it is shown that this can
be mitigated by including drag in UVLM with a BEM-like-approach through look-up tables. Third,
the free wake model in UVLM, required to accurately capture rotor thrust, significantly increases
computational cost. For this reason, a new wake discretisation scheme for the wake convection
equation in UVLM is proposed, in which a coarse discretisation is employed far from the solid
surfaces, which significantly reduces the computational time. Finally, these improvements and
the performance of the three fidelities are analysed in a reference 10 MW wind turbine rotor
demonstrating, in general, good agreement.
Date Issued
2022-02
Date Acceptance
2021-07-25
Citation
Wind Energy, 2022, 25 (2), pp.333-353
ISSN
1095-4244
Publisher
Wiley Open Access
Start Page
333
End Page
353
Journal / Book Title
Wind Energy
Volume
25
Issue
2
Copyright Statement
© 2021 The Authors. Wind Energy published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Sponsor
Commission of the European Communities
Identifier
https://onlinelibrary.wiley.com/doi/10.1002/we.2675
Grant Number
765579
Subjects
Science & Technology
Technology
Energy & Fuels
Engineering, Mechanical
Engineering
aerodynamic loads
spanwise interactions
turbulent wind
unsteady vortex-lattice method
viscous drag
wake convection
FLUID-DYNAMICS
VORTEX
VALIDATION
DESIGN
0906 Electrical and Electronic Engineering
0913 Mechanical Engineering
0915 Interdisciplinary Engineering
Energy
Publication Status
Published
Date Publish Online
2021-08-17