New tidal flume available in UK for offshore testing

The flume has been designed specifically for shallow hydraulic flows - such as those found in coastal regions - and the Joule Centre Wave Flume allows simulation of realistic nearshore wave and current conditions. According to the Joule Centre, it is particularly well suited to the evaluation of marine energy devices and their environmental impact.

The availability of such a facility will be of interest to the growing number of companies developing technologies to harness either wave- or tidal-stream energy. “There are very few flume facilities around the world that can simulate the effects of both current and waves, particularly directionally spread waves. With UK wave power levels among the world’s highest and accounting for over half of Europe’s wave energy, the successful deployment of such technology could make a significant contribution to the UK electricity supply” explains lecturer Dr Tim Stallard.

Waves in the 20 metre long facility are provided by eight Edinburgh Designs’ piston-type wave paddles that can create regular, random, directionally spread or grouped wave conditions. Current velocities up to 0.5m/s at 0.45m depth are achievable and uniquely, currents can be generated simultaneously with any wave condition. The programmable paddles and 5 m width ensure that repeatable tests can be conducted without significant influence from the side walls of the flume. The flume can also be tilted by up to 10° from the horizontal.

This feature is believed to make it the largest tilting facility of its kind anywhere in the world and will be of particular interest to companies needing to test shoreline or estuarine structures.

Manchester Bobber

Key considerations for those developing marine energy technologies are their power output, survivability and environmental impact; all of which are of critical importance to the economic viability of this emerging industry sector.

Previous experiments using the flume have helped to address such challenges. For example, researchers developing a wave-device comprising an array of vertically oscillating floats known as the Manchester Bobber have used the flume facility to improve understanding of performance of an array of devices, as little is known about this for any type of wave energy device.

The experiments have enabled the team to optimise the device’s float-shape as well as study arrays of tidal stream devices to understand the effect of energy extraction on the natural flow.