SuperGen UK Centre for Marine Energy Research Annual ...
Transcript of SuperGen UK Centre for Marine Energy Research Annual ...
SuperGen UK Centre for Marine Energy Research
Annual Assembly 2013
STEP-WEC: STEP CHANGE FOR WAVE
ENERGY CONVERSION THROUGH
FLOATING MULTI-BODY MULTI-MODE
SYSTEMS IN SWELL
.
UKCMER
UKCMER Step-WEC:Consortium of the Universities of Manchester, Oxford and Bath
led by Professor Peter Stansby of University of Manchester
Proposal statement
AIM
To design, analyse and optimise floating systems for wave energy conversion of
approximately 10 MW capacity in swell and mixed swell/wind waves based on
two or more dynamically connected bodies with multi-mode response and to
assess their interaction, particularly power generation, within an array.
UKCMER
Proposal statement
OBJECTIVES
1. To explore wave energy concepts with multi-mode and multi-body response using
simplified nonlinear time stepping modelling, small scale (1:100) wide flume
experiments (Manchester), and 1:20 scale basin testing (Plymouth)
2. To develop power/response prediction methods for multi-mode systems in swell and
random (wind) waves with 1st and 2nd order diffraction theories (using codes
WAMIT and DIFFRACT) providing input into nonlinear time stepping
formulations. Oxford using DIFFRACT.
3. To analyse interaction of swell and random (wind) waves for a wide range of
conditions using DIFFRACT. This analysis is relevant to any form of wave
energy conversion.
4. To measure interaction of directional random waves, swell and currents in the
Edinburgh FloWave wave/current tank, comparing with DIFFRACT.
5. To assess performance of arrays in intermediate-to-deep water (20-100 m). Up to 4
systems will be analysed in a group and periodic boundaries will be used to
analyse infinite rows.
UKCMER
PROGRESS with PhD student Efrain Carpintero Moreno
Proposal 2012
2013 January H=0.02m T=0.85s
Shapes optimised using WAMIT in 2 body heave
UKCMER
3.5 4 4.5 5 5.5 6 6.5 7 7.5 80
0.1
0.2
0.3
0.4
0.5
0.6
0.7
[rad/s]
Po
wer
[W
]
Hs=0.02m
Hs=0.03m
Hs=0.04m
Hs=0.05m
4 4.5 5 5.5 6 6.5 7 7.5 80
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
[rad/s]
Po
wer
[W
]
H = 0.01m
H = 0.015m
H = 0.02m
H = 0.025m
H = 0.03m
H = 0.04m
H = 0.05mregular
random
AVERAGE POWERS
Scale 1:50
Hs=2m
Pav = 180kW
Scale 1:100
H=1m
Pav = 250 kW
SCOPE FOR OPTIMISATION
UKCMER
Next 1:10 scale tests at Plymouth ocean basin
Device built by Cammell Laird
Hydraulic actuator donated by Rexroth Bosch
UKCMER
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18-50
0
50
100
150
200
250
H [m]
Po
ut [
W]
2.2
2.4
2.5
2.6
2.8
3.0
3.2
Regular wavesT [s]
Note:-Solid lines means theesperimental results.
-Dashed lines meansthe Quadratic fitting.
-Valve setting at 1
0 0.05 0.1 0.15 0.2 0.25 0.3-20
0
20
40
60
80
100
120
140
160
Hs [m]
Po
ut [
W]
2.2
2.4
2.6
2.8
3.2
3.6
2.4
2.8
Note:-Solid lines means theesperimental results.
-Dashed lines meansthe Quadratic fitting.
- The square mark means15mins test length.
-Valve setting at 1
Ramdom waves Tp [s]
Regular
Random
JONSWAP
1:16 scale
H=1m T=10s
Pav= 320kW
1:8 scale
Hs=2m Tp=7s
Pav = 150kW
AVERAGE POWERS
UKCMER
But scope for improvement:
• Pivot point was not optimum – known from lab tests
• PTO is simple linear damper – scope for optimisation
• Body motions are large and drag significant – may be reduced
with bigger radius on base – tests planned in lab
FURTHER TESTS AT PLYMOUTH 2013 – 10th -16th December
•Optimising PTO location
•Testing in directional waves
•Testing sea keeping in extreme waves and measuring mooring
loads
Mathematical model of 3 body system has been set up and is being tested
Time stepping with WAMIT coefficients (fully interactive) – method for
handling pivot point incorporated – demonstrates effect of drag coefficient
on power
UKCMER
M4M wave energy conversion
Multi-body Moored Megawatts Multi-Mode
CRITERIA
1. M4M electricity generation cost competitive or less than offshore wind energy
2. Moored floating device for easy deployment and long-term maintenance in port
3. Hydrodynamic design with 3 bodies responding in anti-phase to heave, pitch and surge
modes of motion with variable resonance
4. Broad band frequency response through the different modes to cover offshore wave
conditions
5. Hydraulic power take off on one hinge, accessible from deck for maintenance
6. Power take off automatically adapts to wave conditions
7. Survivable in extreme waves with no power generation
MACE Wave Ltd
Peter Stansby