COAST Laboratory - Facilities

The Ocean Basin is a unique facility that allows waves and currents to be generated at any relative orientation and can be run at different water depths.

This basin can be used to create unidirectional and directional wave fields, regular waves, wave spectra and currents in three dimensions putting it at the forefront of testing for marine renewable energy arrays.

Future developments of the facility include the provision of a wind generation facility.

Wave generation capabilities

The paddles produce regular waves with an approximate maximum height of 0.9m at 0.4 Hz and wave height above 0.2m in a range of 0.166 Hz – 1 Hz.

Wave synthesising software allows long and short-crested spectral sea states to be generated as well as special wave effects. Oblique waves can be comfortably generated up to 40° from normal.

Technical specification

The Ocean Basin is 35m long by 15.5m wide with a moveable floor that allows different operating depths of up to 3m.

Paddles

• waves are generated by 24 individually controlled hinged flap absorbing paddles
• dry-backed 2.0m hinge depth.

Currents

• the recirculating hydraulic system provides longitudinal current up to 0.3m/s for a 2.0m water depth
• a multi-pump recirculating hydraulic system provides the transverse current, enabling a mean flow speed of 0.3m/s at 2.0m depth.

Floor

• slope of up to 6° along the basin maximum point load of 500kg.

Absorbing beach

• convex beach to minimise reflected wave energy
• 1.0m x 0.5m grid of M12 threads throughout the central section of the tank providing mooring capabilities.

One of the key features of the COAST lab is its flexibility. The Coastal Basin allows sediment transport and coastal structures to be studied at scale in a controlled environment.

Wave generation capabilities

The paddles will produce regular waves with a peak wave height of 0.32m. The paddles also function as wave absorbers to mitigate the reflections in the basin. Wave synthesising software allows long and short-crested spectral sea states to be generated, as well as special wave effects.

Technical specification

The Coastal Basin is 15.5m long by 10m wide with a maximum operating depth of 0.5m.

Paddles

• 20 absorbing piston paddles operating as five modules of four paddles
• each paddle is 0.5m wide by 0.5m
• modules may be configured close-coupled as a straight line or arc, or repositioned individually anywhere in the basin.

Currents

• unidirectional flow up to 0.5m/s via five individually controlled pumps across the basin.

Sediment

• pumps are able to deal with large grain sediment (up to 2mm grain size); the equivalent of very coarse sand.

Floor and beach

• can simulate a fixed-bed beach and support sediment and cement beach models
• elemental construction means that it is easily reconfigurable by two people
• all mooring points have M12 threads
• 1.0m x 0.5m grid of M12 threads throughout the central section of the tank providing mooring capabilities.

COAST houses two flumes. A 35m flume and a 20m flume with the capability to be tilted. The inclusion of current circulation in the facility allows tidal energy to be studied as well as wave energy technology.

The novel current circulation technology enables a smooth current to be modelled without disturbing the wave signal, this enables the controlled study of wave-current interaction and wave-current-device interaction.

Wave generation capabilities

Waves up to 0.35m high can be generated. Regular waves, focused waves and plunging breakers are all possible. The paddles absorb reflected wave energy.

Technical specification

• the Sediment Flume is 35m long with a working section of 0.6m wide and a maximum still water depth of 0.8m
• the Tilting Flume is 20m long with a working section of 0.6m wide by 0.6m deep.

Paddles

• absorbing piston paddles, 0.5m by 1.0m
• regular wave heights up to 0.35m
• irregular waves.

Currents

• Reversible flow recirculation of >1.0 m/s including sediment trap.

Sediment

• Pumps are able to deal with large grain sediment (up to 2mm grain size); the equivalent of very coarse sand.

Beach

• Removable flat beach to simulate fixed-bed beach or to support sediment.

Other

• glass sides the full length of the flumes facilitate flow visualisation
• hoist for lifting models, wet sediment and equipment into flume (maximum 1.0 tonne).