Free flow wind speed from a blade-mounted flow sensor

Mads Mølgaard Pedersen*, Torben J. Larsen, Helge Aagaard Madsen , Søren Juhl Andersen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

271 Downloads (Pure)

Abstract

This paper presents a method for obtaining the free-inflow velocities from a 3-D flow sensor mounted on the blade of a wind turbine. From its position on the rotating blade, e.g. one-third from the tip, a blade-mounted flow sensor (BMFS) is
able to provide valuable information about the turbulent sheared inflow in different regions of the rotor. At the rotor, however, the inflow is affected by the wind turbine, and in most cases the wind of interest is the inflow that the wind turbine is exposed to, i.e. the free-inflow velocities. The current method applies a combination of aerodynamic models and procedures to estimate the induced velocities, i.e. the disturbance of the flow field caused by the wind turbine. These velocities are subtracted from the flow velocities measured by the BMFS to obtain the free-inflow velocities. Aeroelastic codes, like HAWC2, typically use a similar approach to calculate the induction, but they use it for the reversed process, i.e. they add the induction to the free inflow to get the flow velocities at the blades, which are required to calculate the resulting aerodynamic forces. The aerodynamic models included in the current method comprise models based on blade element momentum (BEM) for axial and tangential induction, a radial induction model and tip loss correction, and models for skew and dynamic inflow. It is shown that the method is able to calculate the free-inflow velocities with high accuracy when applied to aeroelastic HAWC2 simulations with a stiff structural model while some deviations are seen in simulations with a flexible structure. Furthermore, the method is tested on simulations performed by a flexible structural model coupled with
a large-eddy simulation (LES) flow solver. The results of this higher-fidelity verification confirm the HAWC2- based conclusion.
Original languageEnglish
JournalWind Energy Science
Volume3
Pages (from-to)121-138
ISSN2366-7443
DOIs
Publication statusPublished - 2018

Cite this

@article{e8ed037cabbd44cca4c5a90c1916aac0,
title = "Free flow wind speed from a blade-mounted flow sensor",
abstract = "This paper presents a method for obtaining the free-inflow velocities from a 3-D flow sensor mounted on the blade of a wind turbine. From its position on the rotating blade, e.g. one-third from the tip, a blade-mounted flow sensor (BMFS) isable to provide valuable information about the turbulent sheared inflow in different regions of the rotor. At the rotor, however, the inflow is affected by the wind turbine, and in most cases the wind of interest is the inflow that the wind turbine is exposed to, i.e. the free-inflow velocities. The current method applies a combination of aerodynamic models and procedures to estimate the induced velocities, i.e. the disturbance of the flow field caused by the wind turbine. These velocities are subtracted from the flow velocities measured by the BMFS to obtain the free-inflow velocities. Aeroelastic codes, like HAWC2, typically use a similar approach to calculate the induction, but they use it for the reversed process, i.e. they add the induction to the free inflow to get the flow velocities at the blades, which are required to calculate the resulting aerodynamic forces. The aerodynamic models included in the current method comprise models based on blade element momentum (BEM) for axial and tangential induction, a radial induction model and tip loss correction, and models for skew and dynamic inflow. It is shown that the method is able to calculate the free-inflow velocities with high accuracy when applied to aeroelastic HAWC2 simulations with a stiff structural model while some deviations are seen in simulations with a flexible structure. Furthermore, the method is tested on simulations performed by a flexible structural model coupled witha large-eddy simulation (LES) flow solver. The results of this higher-fidelity verification confirm the HAWC2- based conclusion.",
author = "Pedersen, {Mads M{\o}lgaard} and Larsen, {Torben J.} and {Aagaard Madsen}, Helge and Andersen, {S{\o}ren Juhl}",
year = "2018",
doi = "10.5194/wes-2017-57",
language = "English",
volume = "3",
pages = "121--138",
journal = "Wind Energy Science",
issn = "2366-7443",
publisher = "Copernicus GmbH",

}

Free flow wind speed from a blade-mounted flow sensor. / Pedersen, Mads Mølgaard; Larsen, Torben J.; Aagaard Madsen , Helge; Andersen, Søren Juhl.

In: Wind Energy Science, Vol. 3, 2018, p. 121-138.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Free flow wind speed from a blade-mounted flow sensor

AU - Pedersen, Mads Mølgaard

AU - Larsen, Torben J.

AU - Aagaard Madsen , Helge

AU - Andersen, Søren Juhl

PY - 2018

Y1 - 2018

N2 - This paper presents a method for obtaining the free-inflow velocities from a 3-D flow sensor mounted on the blade of a wind turbine. From its position on the rotating blade, e.g. one-third from the tip, a blade-mounted flow sensor (BMFS) isable to provide valuable information about the turbulent sheared inflow in different regions of the rotor. At the rotor, however, the inflow is affected by the wind turbine, and in most cases the wind of interest is the inflow that the wind turbine is exposed to, i.e. the free-inflow velocities. The current method applies a combination of aerodynamic models and procedures to estimate the induced velocities, i.e. the disturbance of the flow field caused by the wind turbine. These velocities are subtracted from the flow velocities measured by the BMFS to obtain the free-inflow velocities. Aeroelastic codes, like HAWC2, typically use a similar approach to calculate the induction, but they use it for the reversed process, i.e. they add the induction to the free inflow to get the flow velocities at the blades, which are required to calculate the resulting aerodynamic forces. The aerodynamic models included in the current method comprise models based on blade element momentum (BEM) for axial and tangential induction, a radial induction model and tip loss correction, and models for skew and dynamic inflow. It is shown that the method is able to calculate the free-inflow velocities with high accuracy when applied to aeroelastic HAWC2 simulations with a stiff structural model while some deviations are seen in simulations with a flexible structure. Furthermore, the method is tested on simulations performed by a flexible structural model coupled witha large-eddy simulation (LES) flow solver. The results of this higher-fidelity verification confirm the HAWC2- based conclusion.

AB - This paper presents a method for obtaining the free-inflow velocities from a 3-D flow sensor mounted on the blade of a wind turbine. From its position on the rotating blade, e.g. one-third from the tip, a blade-mounted flow sensor (BMFS) isable to provide valuable information about the turbulent sheared inflow in different regions of the rotor. At the rotor, however, the inflow is affected by the wind turbine, and in most cases the wind of interest is the inflow that the wind turbine is exposed to, i.e. the free-inflow velocities. The current method applies a combination of aerodynamic models and procedures to estimate the induced velocities, i.e. the disturbance of the flow field caused by the wind turbine. These velocities are subtracted from the flow velocities measured by the BMFS to obtain the free-inflow velocities. Aeroelastic codes, like HAWC2, typically use a similar approach to calculate the induction, but they use it for the reversed process, i.e. they add the induction to the free inflow to get the flow velocities at the blades, which are required to calculate the resulting aerodynamic forces. The aerodynamic models included in the current method comprise models based on blade element momentum (BEM) for axial and tangential induction, a radial induction model and tip loss correction, and models for skew and dynamic inflow. It is shown that the method is able to calculate the free-inflow velocities with high accuracy when applied to aeroelastic HAWC2 simulations with a stiff structural model while some deviations are seen in simulations with a flexible structure. Furthermore, the method is tested on simulations performed by a flexible structural model coupled witha large-eddy simulation (LES) flow solver. The results of this higher-fidelity verification confirm the HAWC2- based conclusion.

U2 - 10.5194/wes-2017-57

DO - 10.5194/wes-2017-57

M3 - Journal article

VL - 3

SP - 121

EP - 138

JO - Wind Energy Science

JF - Wind Energy Science

SN - 2366-7443

ER -