Automated Steady and Transient CFD Analysis of Flow Over Complex Terrain for Risk Avoidance in Wind Turbine Micro-Siting

Global Flow Solutions, Vestas Wind Systems A/SGregory S. Oxley, Yavor V. Hristov, Seonghyeon Hahn, Cheng-Hu Hu, Søren Mogensen

[14 June 2011, Gregory S. Oxley, Global Flow Solutions, Vestas Wind Systems A/S]

6th OpenFOAM Workshop, Penn State, USA, 14 June, 20112

Presentation Outline

Background: Global Flow Solutions Why CFD for wind turbine micro-siting? 3 levels of CFD analysis

Part 1: Automatic Wind Park Simulator The process Step-by-step

Part 2: ”Forensic” transient analysis Detached-eddy simulation Mesoscale-microscale coupling

6th OpenFOAM Workshop, Penn State, USA, 14 June, 20113

Plant Siting & Forecast (formerly Wind & Site Competence Centre)

PSF is a shared resource focusing on development within:• New software and hardware tools• Uniform calculation methods and reporting• Sharing knowledge across borders• Siting and optimised production calculations• Wind resource measurements / risk assessment• Weather prediction

Staff ~ 30 specialists• CFD specialists• Meteorologists• Ph.D’s in mathematics / statistics / physics• Engineers / technicians• Application developers

Computational Resources• Jetstream - 1,344 cores• Firestorm - 12,222 cores

Vestas C. Europe

Vestas N. Europe

Vestas Pacific

Vestas China

VestasAmericas

Vestas Offshore

Vestas Med.

Plant Siting

& Forecast

6th OpenFOAM Workshop, Penn State, USA, 14 June, 20114

What if local wind effects are ignored?

Gear box may also have excessive loads due to wind turbulence

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Prevention is better than cure

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Automatic Wind Park Simulator – The BUTTON

EmailPointwise

Glyph 2 Script

OpenFOAMCase i

OpenFOAMCase i+1

OpenFOAMCase N

custom

PowerPoint & Excel Reports

Bash Script

custom

custom

Queuing System

Vestas Site Check

W&S engineerW&S engineer W&S engineer

Jetstream

6th OpenFOAM Workshop, Penn State, USA, 14 June, 20117

Vestas Site Check provides industrystandard wasp map contour file

wasp.map -> plot3d conversion and cut to turbine buffer distance

Terrain edge smoothing for even inlets and mesh extrusion considerations

Automatic Windpark SimulatorSteady, turbulent k-ε simulation

6th OpenFOAM Workshop, Penn State, USA, 14 June, 20118

Automatic Windpark SimulatorSteady, turbulent k-ε simulation

VestasFOAMfluent3DMeshToFoam

structured hyperbolic mesh extrusionin Pointwise with Glyph2 macro

utility used to generate hanging nodearchitecture

msh format → OpenFOAM format

unstructured meshing also available

6th OpenFOAM Workshop, Penn State, USA, 14 June, 20119

Automatic Windpark SimulatorSteady, turbulent k-ε simulation

customized from simpleFoam

standard ABL steady profiles

k-epsilon turbulence model with modified constants

customized inlet/outlet and terrainboundary conditions

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Automatic Windpark SimulatorSteady, turbulent k-ε simulation

automated reports (turbulence intensity, inflow angles, wind shear)

Vestas Site Check interface

statistical data for power forecasting

…

6th OpenFOAM Workshop, Penn State, USA, 14 June, 201111

Transient Analysis - Mesoscale – OpenFOAM couplingCase study: Japanese Wind Park

• blades damaged on 2 turbines on 2010-12-27

• suspected strong negative wind shear

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Mesoscale – OpenFOAM couplingCase study: Japanese Wind Park

WRF LES simulation at 111 m horizontal resolution

initialized with GFS

model topography at 1 km resolution

13

ALARM ALARM

Mesoscale – OpenFOAM couplingCase study: Japanese Wind Park

6th OpenFOAM Workshop, Penn State, USA, 14 June, 2011

6th OpenFOAM Workshop, Penn State, USA, 14 June, 201114

Mesoscale – OpenFOAM couplingCase study: Japanese Wind Park

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Summary

Switching to OpenFOAM makes sense: Access to source code Research community involvement Flexibilty Publishable …

Levels of Support: Steady analysis DES forensic analysis Forest modeling

Advanced applications : Dynamically coupled Mesoscale – OpenFOAM for 1hr period of interest

The future has many possibilities!

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