Title: Comparison of free vortex wake and blade element momentum results against large-eddy simulation results for highly flexible turbines under challenging inflow conditions

Abstract

Abstract. Throughout wind energy development, there has been a push to increase wind turbine size due to the substantial economic benefits. However, increasing turbine size presents several challenges, both physically and computationally. Modeling large, highly flexible wind turbines requires highly accurate models to capture the complicated aeroelastic response due to large deflections and nonstraight blade geometries. Additionally, the development of floating offshore wind turbines requires modeling techniques that can predict large rotor and tower motion. Free vortex wake methods model such complex physics while remaining computationally tractable to perform key simulations necessary during the turbine design process. Recently, a free vortex wake model – cOnvecting LAgrangian Filaments (OLAF) – was added to the National Renewable Energy Laboratory's engineering tool OpenFAST to allow for the aerodynamic modeling of highly flexible turbines along with the aero-hydro-servo-elastic response capabilities of OpenFAST. In this work, free vortex wake and low-fidelity blade element momentum (BEM) results are compared to high-fidelity actuator-line computational fluid dynamics simulation results via the Simulator fOr Wind Farm Applications (SOWFA) method for a highly flexible downwind turbine for varying yaw misalignment, shear exponent, and turbulence intensity conditions. Through these comparisons, it was found that for all considered quantities of interest, SOWFA,more » OLAF, and BEM results compare well for steady inflow conditions with no yaw misalignment. For OLAF results, this strong agreement with the SOWFA results was consistent for all yaw misalignment values. The BEM results, however, deviated significantly more from the SOWFA results with increasing absolute yaw misalignment. Differences between OLAF and BEM results were dominated by the yaw misalignment angle, with varying shear exponent and turbulence intensity leading to more subtle differences. Overall, OLAF results were more consistent than BEM results when compared to SOWFA results under challenging inflow conditions.« less

Authors:

Shaler, Kelsey ;

• Search DOE PAGES for author "Shaler, Kelsey"
• Search DOE PAGES for ORCID "0000-0002-7563-3377"

Anderson, Benjamin ;

• Search DOE PAGES for author "Anderson, Benjamin"
• Search DOE PAGES for ORCID "0000-0003-3619-9042"

Martínez-Tossas, Luis A. ;

• Search DOE PAGES for author "Martínez-Tossas, Luis A."
• Search DOE PAGES for ORCID "0000-0003-2353-4999"

Branlard, Emmanuel ;

• Search DOE PAGES for author "Branlard, Emmanuel"
• Search DOE PAGES for ORCID "0000-0002-7750-6128"

Johnson, Nick

Publication Date:

Fri Mar 24 00:00:00 EDT 2023

Research Org.:

National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Wind Energy Technologies Office

OSTI Identifier:

1963327

Alternate Identifier(s):

OSTI ID: 1971892

Report Number(s):

NREL/JA-5000-86056
Journal ID: ISSN 2366-7451

Grant/Contract Number:  

AC36-08GO28308

Resource Type:

Published Article

Journal Name:

Wind Energy Science (Online)

Additional Journal Information:

Journal Name: Wind Energy Science (Online) Journal Volume: 8 Journal Issue: 3; Journal ID: ISSN 2366-7451

Publisher:

Copernicus GmbH

Country of Publication:

Germany

Language:

English

Subject:

17 WIND ENERGY; BEM; CFD; vortex methods