Wind Field Reconstruction in the Induction Zone Olivia Brissette - - PowerPoint PPT Presentation
Wind Field Reconstruction in the Induction Zone Olivia Brissette (Engie) A Round Robin Exercise Daniel Cabezn (EDPR) Marijn F. van Dooren (ForWind) Richard Foreman (UL) Julia Gottschall (Fraunhofer IWES) Paul Housley (SSE) Alkistis
A Round Robin Exercise
Nicolai Gayle Nygaard WESC 2019
Olivia Brissette (Engie) Daniel Cabezón (EDPR) Marijn F. van Dooren (ForWind) Richard Foreman (UL) Julia Gottschall (Fraunhofer IWES) Paul Housley (SSE) Alkistis Papetta (Fraunhofer IWES) Anantha P. K. Sekar (ForWind) Eric Simley (NREL) Chris Slinger (ZX Lidars)
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Motivation
U2.5D/U∞ = ?
Data filtered for – Freestream wind directions – Turbine operating normally Data shared – Lidar radial wind speeds at 10 ranges – Lidar tilt and roll angles – Experiment geometry
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Round robin data
www.aventlidartechnology.com
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Round robin format Report back using Excel template Dialogue to eliminate misunderstandings Lidar LOS wind speeds Participant choice Result
Induction model
1 2 3
8 4 1 1 1D centreline Troldborg & Forsting CFD Vortex sheet
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Round robin contributions
1D centreline
– Medici et al (2011) – Applies on induction zone centreline 1. Reconstruct centreline wind speed from LOS 2. Fit to induction model
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Induction models
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Induction models
3 participants Neglect 0.11D lidar position offset 5 participants Include lidar position offset
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Induction models
Troldborg & Forsting
– Troldborg & Forsting (2017) – Combines 1D model with radial induction profile – Fit LOS directly
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Induction models
1D centreline
– Medici et al (2011) – Applies on induction zone centreline 1. Reconstruct centreline wind speed from LOS 2. Fit to induction model
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Wind speed reduction
Fitting only outer lidar ranges Generic thrust curve used to find induction factor
CFD
– RANS with actuator disk – Guessed turbine thrust curve 1. Reconstruct centreline wind speed from LOS 2. Compare with CFD results 3. Extrapolate to 10D upstream distance
Troldborg & Forsting
– Troldborg & Forsting (2017) – Combines 1D model with radial induction profile – Fit LOS directly
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Induction models
1D centreline
– Medici et al (2011) – Applies on induction zone centreline 1. Reconstruct centreline wind speed from LOS 2. Fit to induction model
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Wind speed reduction
CFD
– RANS with actuator disk – Guessed turbine thrust curve 1. Reconstruct centreline wind speed from LOS 2. Compare with CFD results 3. Extrapolate to X=-10D
Vortex sheet
– Branlard (2015) – Full 2D analytical model – Resolves axial and transverse motion – Includes ground effect
Troldborg & Forsting
– Troldborg & Forsting (2017) – Combines 1D model with radial induction profile – Fit LOS directly
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Induction models
1D centreline
– Medici et al (2011) – Applies on induction zone centreline 1. Reconstruct centreline wind speed from LOS 2. Fit to induction model
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Wind speed reduction
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Induction factor
Betz limit
𝑉 𝑦 = 0 = 1 − 𝑏 𝑉∞
Centreline, Medici et al. formula
U1 > U2
U1 U2
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Conclusions
Larger induction effect
Splitting wind field reconstruction and induction model Integrating wind field reconstruction and induction model
Larger induction effect
Including only induction effect on axial motion Including induction effect on both axial and transverse motion
Larger induction effect
Isolated rotor Including ground effect and other turbines
Approximately 1% reduction of wind speed 2.5D upstream
Objective – Model induction from entire array – Find influence on the nacelle lidar measurements Dataset – Same as Round Robin v1 – Wind farm details added Timeline – Starts today – Deadline for submission: 1 November 2019
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Round Robin – version 2
NICNY@orsted.dk