ABL simulations with uncertain weather parameters and

The project has received funding from the European Union’sHorizon 2020 research and innovation programme underthe Marie Sklodowska-Curie grant agreement No 860101

CONTEXT PROBLEM DEFINITION

[1] R. K. Amiet, “Noise due to turbulent flow past a trailing edge,” Journal of sound and vibration 47(3), 387-393 (1976).[2] J. N. Sørensen and W. Z. Shen, “Numerical modeling of wind turbinewakes,” J. Fluids Eng. 124, 393 (2002).[3] H. Glauert, “Airplane propellers,” in Aerodynamic Theory, edited by W. F. Durand (Dover, New York, 1963), pp. 169–360.

ABL simulations with uncertain weather parameters and impact on WT performance and near-field noise

zEPHYR Marie Skłodowska-Curie project: Towards a more efficient exploitation of on-shore and urban wind energy resourcesBaris Kale*1,2, Sophia Buckingham1, Alvaro Cuerva Tejero2, Jeroen van Beeck1

1Environmental and Applied Fluid Dynamics Department, von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse, Belgium2Aerospace Engineering Department, Universidad Politécnica de Madrid, Madrid, Spain

*baris.kale@vki.ac.be

The main problem of numerical studies regarding the performanceprediction of wind turbines is to impose inadequate turbulent inflowconditions.

Using re-analysis data set including atmospheric and land-soil variablesand high-resolution topography results in an accurate representation ofwind turbine’s aerodynamic features.

• TE noise is caused by scattering ofboundary-layer vortical structures inacoustic waves in the vicinity of theairfoil TE.

METHODOLOGYWRF is used to force mesoscale flow to the inner-most microscaledomain to perform LES with WT parameterization. WRF output is laterfed to a RANS solver for the investigation of wind turbine noise.

OBJECTIVES• Implement a WT parameterization scheme mimicking an active

turbine yawing mechanism and perform multiscale ABL simulations ina multiphysics solver (e.g., Weather Research and Forecasting(WRF) model) using Large Eddy Simulation (LES) technique.

• Couple WRF-LES outputs with semi-analytical noise models based onReynolds-Averaged Navier-Stokes (RANS) simulation inputs forshort-range noise prediction.

WIND TURBINE PARAMETERIZATION

𝝏𝝏𝑼𝑼𝒊𝒊

𝝏𝝏𝝏𝝏= −

𝟏𝟏𝝆𝝆𝑮𝑮(𝒓𝒓, 𝒍𝒍)𝑭𝑭𝒊𝒊 𝑮𝑮(𝒓𝒓, 𝒍𝒍) =

𝒆𝒆(−𝒅𝒅𝒓𝒓

𝟐𝟐

𝟐𝟐𝝈𝝈𝒓𝒓𝟐𝟐+𝒅𝒅𝒍𝒍

𝟐𝟐

𝟐𝟐𝝈𝝈𝒍𝒍𝟐𝟐)

𝟐𝟐𝟐𝟐𝝈𝝈𝒓𝒓𝝈𝝈𝒍𝒍where

Actuator element forceFiltered

momentum tendency

Gaussian smoothing term

• Sørensen and Shen [2] proposed Actuator Line Model (ALM) tosimulate wind turbine blades by radially distributing turbine forces alongblade-representing lines.

• The ALM uses Blade-Element-Momentum (BEM) theory by Glauert[3] and the computed forces are added to the filtered Navier-Stokesmomentum equations as a sink term in a high-fidelity LES solver.

TRAILING EDGE NOISE MODELING

𝑺𝑺𝒑𝒑𝒑𝒑(𝒙𝒙,𝝎𝝎) = 𝒅𝒅𝒌𝒌𝒌𝒌𝒌𝒌𝟐𝟐𝝈𝝈𝟎𝟎

𝟐𝟐

𝜱𝜱𝒑𝒑𝒑𝒑(𝝎𝝎)ℓ𝒚𝒚(𝝎𝝎,𝑲𝑲𝒚𝒚) 𝓛𝓛(𝒙𝒙,𝑲𝑲𝒙𝒙,𝑲𝑲𝒚𝒚) 𝟐𝟐

Power spectraldensity of thesound pressure

Observer/airfoilposition

Wall pressure spectrum Spanwise correlation length

Airfoil response function

Amiet [1] theory allows predicting TE noise for airfoil-like profiles.Assuming a large airfoil aspect ratio ⁄(𝑳𝑳 𝒄𝒄):

The atmospheric boundary layer (ABL) is the lower part of thetroposphere in contact with the Earth's ground. ABL consists of differentlayers whose structural properties change in a daily cycle.

Wind turbines (WTs) operating within the ABL are affected by changes inturbulence structure and dynamics and are therefore subject to constantlychanging wind flow conditions. Realistic inflow variability and boundaryconditions are essential to precisely model the aerodynamic andaeroacoustic behaviors of wind turbines.

• Trailing-edge (TE) noise is one of themost contributing noise source in windturbine applications and perceived inwhole frequency range.