Discontinuous Galerkin methodology for Large-Eddy Simulations of wind turbine airfoils

A. Frére, Niels N. Sørensen, K. Hillewaert, G. Winckelmans

Research output: Contribution to journalConference articleResearchpeer-review

224 Downloads (Pure)

Abstract

This paper aims at evaluating the potential of the Discontinuous Galerkin (DG) methodology for Large-Eddy Simulation (LES) of wind turbine airfoils. The DG method has shown high accuracy, excellent scalability and capacity to handle unstructured meshes. It is however not used in the wind energy sector yet. The present study aims at evaluating this methodology on an application which is relevant for that sector and focuses on blade section aerodynamics characterization. To be pertinent for large wind turbines, the simulations would need to be at low Mach numbers (M ≤ 0.3) where compressible approaches are often limited and at large Reynolds numbers (Re ≥ 106) where wall-resolved LES is still unaffordable. At these high Re, a wall-modeled LES (WMLES) approach is thus required. In order to first validate the LES methodology, before the WMLES approach, this study presents airfoil flow simulations at low and high Reynolds numbers and compares the results to state-of-the-art models used in industry, namely the panel method (XFOIL with boundary layer modeling) and Reynolds Averaged Navier-Stokes (RANS). At low Reynolds number (Re = 6 × 104), involving laminar boundary layer separation and transition in the detached shear layer, the Eppler 387 airfoil is studied at two angles of attack. The LES results agree slightly better with the experimental chordwise pressure distribution than both XFOIL and RANS results. At high Reynolds number (Re = 1.64 × 106), the NACA4412 airfoil is studied close to stall condition. In this case, although the wall model approach used for the WMLES is very basic and not supposed to handle separation nor adverse pressure gradients, all three methods provide equivalent accuracy on averaged quantities. The present work is hence considered as a strong step forward in the use of LES at high Reynolds numbers.
Original languageEnglish
Article number022037
Book seriesJournal of Physics: Conference Series (Online)
Volume753
Number of pages11
ISSN1742-6596
DOIs
Publication statusPublished - 2016
EventThe Science of Making Torque from Wind 2016 - Technische Universität München (TUM), Munich, Germany
Duration: 5 Oct 20167 Oct 2016
Conference number: 6
https://www.events.tum.de/?sub=29

Conference

ConferenceThe Science of Making Torque from Wind 2016
Number6
LocationTechnische Universität München (TUM)
CountryGermany
CityMunich
Period05/10/201607/10/2016
Internet address

Bibliographical note

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Published under licence by IOP Publishing Ltd

Keywords

  • Applied fluid mechanics
  • General fluid dynamics theory, simulation and other computational methods
  • Numerical approximation and analysis
  • Power and plant engineering (mechanical engineering)
  • Mechanical components
  • Numerical analysis
  • Fluid mechanics and aerodynamics (mechanical engineering)
  • aerodynamics
  • blades
  • flow simulation
  • Galerkin method
  • Navier-Stokes equations
  • wind turbines
  • angle of attack
  • Eppler 387 airfoil
  • RANS
  • Reynolds averaged Navier-Stokes
  • panel method
  • Reynolds numbers
  • Mach numbers
  • blade section aerodynamics characterization
  • wind energy sector
  • DG methodology
  • wind turbine airfoil
  • LES methodology
  • large eddy simulation
  • discontinuous Galerkin methodology

Cite this