Who Are AWS Ocean Energy? AWS develop technology in the renewable marine energy sector. Their goal is to develop a multi megawatt wave energy generator. We have worked in partnership with AWS Ocean Energy on a vast range of projects since 2009 and this close working relationship has led to the formation of 4c Engineering based in Inverness.
Due to the competitive nature of work carried out in wave energy much of what we have done must be kept confidential. However here is a sneak peek into 3 projects we have been involved in with AWS:
Solving the problem of how to attach a multi tonne diaphragm.
Development of prototypes for scale testing of AWS concept.
Development of a device to replicate the pressure effect of waves.
Whilst working in collaboration with their internal team our continued involvement with AWS has provided them with multiple outputs that include; Deep Dive brainstorming sessions, complex CAD 3D models for analysis, model making, scale prototypes for physical testing, product and process visualisations.
Our challenge was to investigate the concept of the diaphragm material itself. Simon Grey, the CEO at AWS was interested in exploring the idea of a diaphragm that did not strain. At this time this was a major change from the flexible rubber diaphragm that was being proposed. The 4c studio and in house workshop facilities combined with our freethinking attitude provide an ideal environment for visionary engineers like Simon to explore then bounce ideas off like-minded individuals. During these intense 1 day sessions we allow the senior team from our client company a free (but highly focused) space where they can remove themselves from the day to day constraints of running their company. The output from this session helped confirm Simon’s hunch, that a non-straining displacement diaphragm was the correct route forward. Shortly after the engineering direction was changed on this fundamental component. The 4 minute video shows a summary of the day.
AWS had a tight time schedule in which to launch and test their 7 metre diameter, 3.5 tonne prototype test rig. They required a design engineering team to handle the structural design and production of fabrication drawings required to produce the skeletal frame of the device. 4c Design took on the job and working in collaboration with their structural engineering partners delivered a fully engineered drawing package within 10 days, thus allowing AWS to begin manufacture and assembly of this pivotal test device. Click here to watch the device in action.
Leading on from the Loch Ness test the next challenge was to produce a Mk2 prototype at 1/15th Scale. This would be a much more complex machine full of instrumentation to take to one of the world’s largest wave test tanks – MARIN.
The design challenges included producing a modular ‘cell’ so the configuration of the device could be transformed to try out different options, the load bearing steel framework needed to come apart for road transport. One element of this was being tasked with developing an optimum airflow duct for the internal saddle. To do this work we used a ‘form finding’ technique, combining the power of CAD package Rhino/Grasshopper & Galapagos to work its way through thousands of iterations of designs, like natural selection in evolution, the computer program searches out the ‘fittest’ solution. The 1min video below shows some of the steps in the process.
In order to calibrate the prototype, AWS needed a blower to simulate the sinusoidal movement of air that the diaphragms would generated when actuated by waves. So they set us the challenge – 250 litres of air in one second. Through our civil engineering associates we were able to source a large diameter section of glass fibre water pipe, concentricity and a smooth internal surface where an important actor in achieving the seal. A custom-built piston powered by motor displaced the air, in full flow the device was reminiscent of a steam locomotive!