Recently, ARC Marine have had the opportunity to carry out scaled down testing at the University of Plymouth Coastal, Ocean and Sediment Transport (COAST) Laboratory, under the Marine-I project, which is European Regional Development Funding (ERDF). Back in May 2018, ARC Marine carried out an initial round of testing in the COAST laboratory, using the 20 meter current and wave flume. The second round of testing was carried out in the coastal basin. This basin is 15.5m long and 10m wide, with an operating depth of 0.5m. It has a Vectrino for measuring current, and a wave gauge for measuring wave conditions. The tests were run and supervised by Dr Oscar de la Torre, a research fellow at the University of Plymouth.
The testing was over 3 weeks, where different configurations of Reef Cubes were tested around a wind turbine mono pile, to decrease the effects of, or completely prevent scour. It was run with a simulated depth of 8m at a 1:40 scale, and it was put through extreme current and wave conditions that would be expected once every 50 years.
Just like the previous testing, all tests were recorded with a HD camera taking photos every few seconds, and scour depths were recorded using a traverse laser scanner, to capture in greater detail sediment deposits and movement (Figure 1).
Figure 1: Sediment basin at the COAST Lab ready for testing
Modelling was a very important part of the testing. In comparison to a full-scale trial, the modelling is both a lower cost and a much lower risk. It allows for configurations of Reef Cubes to be tested on a small, low cost scale, so that there is a greater degree of confidence in the solutions, before proceeding to a full size trial. It tests the Reef Cubes in a safe environment, where they can be tested to their limits, without risking damage to the surrounding assets. Minor alterations can be made throughout the experiment, to improve their performance and stability. Overall, 3000 models were made for the testing.
Figure 2: One of the ARC Marine team prepping the models ready for testing
This article was written by Zoe Barnes – Intern student from the University of Plymouth – Environmental Science BSC