Hydrodynamics of tidal stream energy devices with two rows of blades

Peter JohnsonPhD student, UCL Mechanical engineering, andLecturer, Nazarbayev University School of Engineering

with Adam Wojcik and Kevin Drake, UCL Mechanical Engineering

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Hydrodynamics of tidal stream energy devices with two rows of blades

Peter JohnsonPhD student, UCL Mechanical engineering, andLecturer, Nazarbayev University School of Engineering

with Adam Wojcik and Kevin Drake, UCL Mechanical Engineering

blade speed

water speed

relative speed

drag

lift

Guy cable

Sea Bed

Guy cable

Guy cable

Guy cable

cable

cable

cable

cable

SupportColumn

Generator

θ

Fn

Ft

Fn

Ft

sinnFN

sinnFN

2 m

0.5

m

chain

wheel

shaft

shaft

blade

trackSlider

Aluminium plate

Predictions

W

2R

Clockwise:

Θ = 0.5

Clockwise:

Θ = 0

FnFt

M

y

x

R

Definitions

2D vortex model results

Pow

er c

oeffi

cien

t

Blade speed

o – Moonraker, + – Darrieus

2D point vortex model using empirical blade data

Blade(carbon fibre)

chain

wheelAttachment link

S/steel shaft

Nylon pads (rapid prototyped)

Aluminium plates

VideoPII_001.wmv

Distributed load

Strain gaugesBending member

Blade(hollow carbon fibre shell)

TracksTracksBlade

Blade(hollow carbon fibre shell)

Blade instrumentation concepts

How to record the signal from the strain gauge?

Carbon fibre blade

61 mm

Microlog main PCB

Microlog bluetooth transceiver

9 mm

Microlog filter circuit (inside blade)

Terminals

Polished surfaces for strain gauges

Holes for cables

Holes for

dowel pins

18 mm

Junction

board

Stainless steel rod

Dual strain gauge

Microlog main PCB

Nano batteriesBending member

Microlog PCBs

Charging circuit

Filled with Silicone

Dowel pins

Epoxy escape holes

Filled with epoxy

Flush dowel pins

QinetiQ Plc., Naval testing facilities, Haslar, near Portsmouth, UK

Results: Fourier fitting

W

2R

Clockwise:

Θ = 0.5

Clockwise:

Θ = 0

FnFt

M

y

x

R

Recap: definitions

Normal force

Normal force

Normal force

Summary of results for force normal to blade’s motion, Fn

Data here is for results with 3 blades

Tangential force; 6 blades

Tangential force; 6 blades

x – experimento – vortex model (infinite blades) – vortex model (finite blades) for 6 blades

6 blades

Tangential force; 3 blades

Track

wheelscarriage

 

 

TrackNo Track

tangent

  

Centrifugal force

Cable-tie (slack) Tie clip

(tight)

Cable-tie connects trailing edge of blade to chain, to limit pitching during corners

No Track

tangent

  

Centrifugal force

ideal practical

Cable-tie extended

3 blades

3 blades

Many thanks to …

Kevin Drake, Adam Wojcik, Neil Collins,Richard Winn, Dan Fone, Peter Kelly, Sinan Hasan, Savvas Achilleos, Ian Eames,

Christian Klettner, Andre Nicolle, Christian Jonsson, Tim McDonald, Tristan Smith, Ben Tompsen, Chris Pyke, Mike Johnson, Joachim Baumgaertner,

And support from QinetiQ Plc., Norwin Electrics, Ashley Power Ltd., JRD Ltd. , NCGE, NESTA, EPSRC, UCL.

Thank you… and questions

www.londonmarinepower.co.uk(from Kaz: www.londonmarinepower.co.uk.nyud.net )

Results: Fourier fitting