AWS Ocean Energy work in the renewable marine energy sector and have developed an innovative floating wave energy convertor. Their ambition is to develop reliable, affordable and operable offshore power stations. 4c engineers have contributed at every stage of the device development.
As part of the development programme for the AWS-III wave energy convertor, it was determined that a large scale technology demonstrator and test rig of the absorber subsystem was required, to be deployed in a marine environment.
The technology demonstrator consists of a floating concrete caisson, upon which the absorber subsystem, process air pipework and PTO container are mounted. Our engineers were involved at every stage of design, construction, assembly and operation.
Our engineers delivered the design of the complete test rig, including the following elements:
Installed and operational at its site in Scapa Flow, the test rig provides a platform for the following activities necessary for the AWS-III development programme:
The absorber subsystem consists of a flexible air-water interface (AWI, or “diaphragm”) and a supporting structure or “saddle”. The saddle consists of a large fabricated steel structure, which provides support to the diaphragm, and transfers wave loading back to the hull structure of the wave energy convertor (WEC). It also provides the attachment and sealing point for the diaphragm, the connection to the process air system, and a platform for the mounting of instrumentation.
The saddle surface is a complex formed 3D shape with a supporting structure of major and minor stiffeners. Our engineers undertook engineering design of this system from concept through to a detailed CAD package for fabrication. The total fabricated mass of the saddle was around 12 tonnes and measured 9 x 4.5 x 1.5 m. It was designed to withstand sea states of Hs = 3.0 m, taking into account wave slam events as experienced in scale model trials.
Our engineers delivered the design of the saddle subsystem, including the following elements:
The process air system consists of a collection of components including ductwork, adjustable pipe stands, valves and valve stands, and a water-trap sump with water sensors. This system connects the flow of air from the absorber to a plenum chamber contained within the concrete caisson which forms the project’s base platform, and provides the means by which air can be routed through a power take-off unit.
Our engineers delivered detailed engineering design of these components from concept through to a comprehensive package of manufacturing drawings. These components have now been fabricated, and assembled at the test site at Lyness, Orkney.
Our engineers undertook design of a variety of items, including the following: