The Oscillating Wave Surge Converter

1
The Oscillating Wave Surge Converter

• Matt Folley
• Trevor Whittaker
• Max Osterried

Queens University Belfast
A UK EPSRC project in collaboration
with Manchester Metropolitan University Centre
for Mathematical Modelling and Flow Analysis
2
Experience of QUB in wave power research

• 1982 wave-powered navigation buoy
• 1987 75 kW shoreline OWC prototype
• 2001 LIMPET 500 kW shoreline OWC

3
The Oscillating Wave Surge Converter concept

• A working surface moving predominantly
  horizontally
• to couple strongly with the water particle motion
  in shallow water
• A water column behind the working surface
• To tune the device to the predominant wave
  frequency
• To minimise losses due to reflection

4
Some possible OWSC conceptual configurations
5
Comparison of bottom and top hinged OWSCs

• Top hinged OWSC
• Better matching of water particle motion as water
  depth decreases
• Accessible bearings / power take-off
• Paddle can swing through 360

• Bottom hinged OWSC
• Better matching of water particle motion as water
  depth increases
• Inaccessible bearings / power take-off
• End-stop problem

6
OWSC testing programme
QUB 0.35 m wide wave flume

• 1/40th scale model
• 6 Bretschneider sea-states
• Energy period, Te 7, 10 , 13 secs
• Incident wave power, Pi 10, 20, 40 kW/m
• 3 wave probe reflection analysis

7
OWSC model

• Proney brake used to simulate constant pressure
  hydraulics

8
Optimum damping for the OWSC
9
Power audit for the OWSC
10
Maximum capture factors of the OWSC, LIMPET and
Pendulor
Pendulor
LIMPET
OWSC
0.50
0.19
0.61
Te7 secs, Pi10kW/m
0.46
0.17
0.56
Te7 secs, Pi20kW/m
0.43
0.38
0.42
Te10 secs, Pi10kW/m
0.41
0.35
0.41
Te10 secs, Pi20kW/m
0.38
0.30
0.38
Te10 secs, Pi40kW/m
0.33
0.36
0.31
Te13 secs, Pi40kW/m
11
Embodiment 1 single shoreline OWSC
12
Embodiment 2 single near-shore OWSC
13
Embodiment 3 OWSC near-shore terminator array
14
Improved OWSC control strategies

• Improve damping characteristics
• Variable pressure hydraulics
• Variable displacement pump
• Improve OWSC phase characteristics
• Complex conjugate control
• Latching

15
Conclusions

• The OWSC is a promising shoreline / near-shore
  wave energy converter
• Logical progression from current technology
• Further improvements possible
• Optimisation of configuration - hydrodynamic
  analysis
• Optimisation of control - dynamic analysis
• Optimisation of construction cost/benefit
  analysis