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The Single tree experiment
Ebba Dellwik, Jakob Mann, Andrey Sogachev, Niels Troldborg
Horia Hangan, Tim Newson and Barry Gardiner
29 August 2016 DTU Wind Energy, Technical University of Denmark
Outline of presentation • Who? Why? How? • Experimental facilities • The single tree • CFD and modeling
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29 August 2016 DTU Wind Energy, Technical University of Denmark
Who?
Wind tunnel experts
Tree experts Wind experts
The single tree experiment Who?
29 August 2016 DTU Wind Energy, Technical University of Denmark
The single tree experiment Why? • Poor wind ressource assessment for wind energy
• Poor wind risk assessments for trees
• Poor air quality assessment in urban areas
• Small-scale tree configurations are
overlooked in land surface modelling
Trees are a fundamental part of our landscape, yet
their interaction with the wind is poorly understood.
29 August 2016 DTU Wind Energy, Technical University of Denmark
The single tree experiment How?
H1
H2
Operational models
Single tree,
multiple trees
Advanced modelling
29 August 2016 DTU Wind Energy, Technical University of Denmark
6 9 December 2016
Planned trees experiment in the WindEEE Dome, University Western Ontario, Canada
Wind Engineering, Energy and Environment
3 Dimensional wind-test chamber
Shape of a hexagon
106 individual fans
Physical modelling of high intensity wind
systems, tornados, downbursts and gust fronts
Large scale models, manipulation of inflow and
boundary conditions
Dimensions: 25m in diameter
WindEEE Dome
29 August 2016 DTU Wind Energy, Technical University of Denmark
‘Scaled’ tree wind-tunnel tests • Norway spruce sapling
– Picea abies (L.) – Dimensions
• Height: 1.5 m – Removed fine roots
• Ottawa sand substrate • Sub-failure and windthrow conditions • Open country profile (turbulence int = 18%)
29 August 2016 DTU Wind Energy, Technical University of Denmark
Strain Gauge set-up on the root plate
95mm
Wind
Windward root top
Lee root top
Lee root side
Windward root side
95mm
Location of root strain gauges
29 August 2016 DTU Wind Energy, Technical University of Denmark
1.5cm
WIND
13.5cm
12.5cm REF Accelerometer lee
root
Top Accelerometer lee root
Side Accelerometer lee root
Top Accelerometer windward root
Side Accelerometer windward root
1.5cm
Location of root accelerometers
29 August 2016 DTU Wind Energy, Technical University of Denmark
Planned WindScanner experiment
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29 August 2016 DTU Wind Energy, Technical University of Denmark
6 m tall
6 m wide Summer towards southwest
This is a good tree because
1. It is deciduous
2. It has the right size
3. It is a strong tree
4. It is on our campus
29 August 2016 DTU Wind Energy, Technical University of Denmark
Winter towards northwest
29 August 2016 DTU Wind Energy, Technical University of Denmark
Tree structure determination
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Leica total station:
1 cm resolution
8 different scans
29 August 2016 DTU Wind Energy, Technical University of Denmark
Scanning results
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29 August 2016 DTU Wind Energy, Technical University of Denmark
Scanning results
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29 August 2016 DTU Wind Energy, Technical University of Denmark
Scanning results
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The different
colours denote the
results from the
eight different scans.
29 August 2016 DTU Wind Energy, Technical University of Denmark
First triangulation results: How much of the tree can we resolve?
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29 August 2016 DTU Wind Energy, Technical University of Denmark
CFD models of tree: How much of the resolved tree can be resolved in the wind model?
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?
Large-Eddy Simulation
29 August 2016 DTU Wind Energy, Technical University of Denmark
The Single-tree experiment: applied aspects
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A coupling between these two
models has been initiated!
29 August 2016 DTU Wind Energy, Technical University of Denmark
Conclusions • The Single tree experiment project has just started • We have found a tree that we will study and characterized it with
terrestrial laser scanning. • The development of a model tree has started.
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