LES simulation and experimental validation of the unsteady aerodynamics of blunt wind turbine airfoils

Guofu Wang, Lei Zhang*, Wen Zhong Shen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In order to investigate the unsteady performance of blunt wind turbine airfoils caused by boundary layer separation and wake eddies, this paper studies the aerodynamic performance by large eddy simulation (LES) and wind tunnel experiment at a Reynolds number of 2.62×10^5. The blunt airfoils are obtained by enlarging the trailing edge of the DU 91-W2-250 airfoil to 6% and 10% chords symmetrically on both pressure and suction sides of the airfoil. The simulation was carried out with the incompressible finite-volume Navier-Stokes code EllipSys3D; and, the experiment was done in a wind tunnel with a cross-section of 0.5m × 0.5m by measuring the surface pressure and wake velocities using ESP-64HD pressure scanner and TSI hot-wire anemometer. The unsteady wake was captured by hot-wire in the wind tunnel, and LES with EllipSys3D. Both experiment and LES show that the spectrum of aerodynamic forces has a broadband nature which is in coincidence with the wake eddies, implying that the unsteady Kármán vortex sheet is the driving mechanism of the force fluctuation. Moreover, the trailing edge size affects the separation bubbles and transition process in the boundary layer. It shows that the boundary layer near the leading edge is unstable in the spanwise direction, which is characterized by low frequency waves.
Original languageEnglish
JournalEnergy
Volume158
Pages (from-to)911-923
Number of pages13
ISSN0360-5442
DOIs
Publication statusPublished - 2018

Keywords

  • Blunt airfoil
  • Wake
  • Unsteady
  • Transition
  • Large eddy simulation
  • Experiment

Cite this

@article{04ee67046a9a4f4ea090b29c5ca81151,
title = "LES simulation and experimental validation of the unsteady aerodynamics of blunt wind turbine airfoils",
abstract = "In order to investigate the unsteady performance of blunt wind turbine airfoils caused by boundary layer separation and wake eddies, this paper studies the aerodynamic performance by large eddy simulation (LES) and wind tunnel experiment at a Reynolds number of 2.62×10^5. The blunt airfoils are obtained by enlarging the trailing edge of the DU 91-W2-250 airfoil to 6{\%} and 10{\%} chords symmetrically on both pressure and suction sides of the airfoil. The simulation was carried out with the incompressible finite-volume Navier-Stokes code EllipSys3D; and, the experiment was done in a wind tunnel with a cross-section of 0.5m × 0.5m by measuring the surface pressure and wake velocities using ESP-64HD pressure scanner and TSI hot-wire anemometer. The unsteady wake was captured by hot-wire in the wind tunnel, and LES with EllipSys3D. Both experiment and LES show that the spectrum of aerodynamic forces has a broadband nature which is in coincidence with the wake eddies, implying that the unsteady K{\'a}rm{\'a}n vortex sheet is the driving mechanism of the force fluctuation. Moreover, the trailing edge size affects the separation bubbles and transition process in the boundary layer. It shows that the boundary layer near the leading edge is unstable in the spanwise direction, which is characterized by low frequency waves.",
keywords = "Blunt airfoil, Wake, Unsteady, Transition, Large eddy simulation, Experiment",
author = "Guofu Wang and Lei Zhang and Shen, {Wen Zhong}",
year = "2018",
doi = "10.1016/j.energy.2018.06.093",
language = "English",
volume = "158",
pages = "911--923",
journal = "Energy",
issn = "0360-5442",
publisher = "Elsevier",

}

LES simulation and experimental validation of the unsteady aerodynamics of blunt wind turbine airfoils. / Wang, Guofu; Zhang, Lei; Shen, Wen Zhong.

In: Energy, Vol. 158, 2018, p. 911-923.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - LES simulation and experimental validation of the unsteady aerodynamics of blunt wind turbine airfoils

AU - Wang, Guofu

AU - Zhang, Lei

AU - Shen, Wen Zhong

PY - 2018

Y1 - 2018

N2 - In order to investigate the unsteady performance of blunt wind turbine airfoils caused by boundary layer separation and wake eddies, this paper studies the aerodynamic performance by large eddy simulation (LES) and wind tunnel experiment at a Reynolds number of 2.62×10^5. The blunt airfoils are obtained by enlarging the trailing edge of the DU 91-W2-250 airfoil to 6% and 10% chords symmetrically on both pressure and suction sides of the airfoil. The simulation was carried out with the incompressible finite-volume Navier-Stokes code EllipSys3D; and, the experiment was done in a wind tunnel with a cross-section of 0.5m × 0.5m by measuring the surface pressure and wake velocities using ESP-64HD pressure scanner and TSI hot-wire anemometer. The unsteady wake was captured by hot-wire in the wind tunnel, and LES with EllipSys3D. Both experiment and LES show that the spectrum of aerodynamic forces has a broadband nature which is in coincidence with the wake eddies, implying that the unsteady Kármán vortex sheet is the driving mechanism of the force fluctuation. Moreover, the trailing edge size affects the separation bubbles and transition process in the boundary layer. It shows that the boundary layer near the leading edge is unstable in the spanwise direction, which is characterized by low frequency waves.

AB - In order to investigate the unsteady performance of blunt wind turbine airfoils caused by boundary layer separation and wake eddies, this paper studies the aerodynamic performance by large eddy simulation (LES) and wind tunnel experiment at a Reynolds number of 2.62×10^5. The blunt airfoils are obtained by enlarging the trailing edge of the DU 91-W2-250 airfoil to 6% and 10% chords symmetrically on both pressure and suction sides of the airfoil. The simulation was carried out with the incompressible finite-volume Navier-Stokes code EllipSys3D; and, the experiment was done in a wind tunnel with a cross-section of 0.5m × 0.5m by measuring the surface pressure and wake velocities using ESP-64HD pressure scanner and TSI hot-wire anemometer. The unsteady wake was captured by hot-wire in the wind tunnel, and LES with EllipSys3D. Both experiment and LES show that the spectrum of aerodynamic forces has a broadband nature which is in coincidence with the wake eddies, implying that the unsteady Kármán vortex sheet is the driving mechanism of the force fluctuation. Moreover, the trailing edge size affects the separation bubbles and transition process in the boundary layer. It shows that the boundary layer near the leading edge is unstable in the spanwise direction, which is characterized by low frequency waves.

KW - Blunt airfoil

KW - Wake

KW - Unsteady

KW - Transition

KW - Large eddy simulation

KW - Experiment

U2 - 10.1016/j.energy.2018.06.093

DO - 10.1016/j.energy.2018.06.093

M3 - Journal article

VL - 158

SP - 911

EP - 923

JO - Energy

JF - Energy

SN - 0360-5442

ER -