Cape Horn wraps up CFD validation for Spiralis Energy’s tidal test rig (Video)

The UK-based marine technology consultant Cape Horn Engineering has completed the first validation of its computational fluid dynamics (CFD) analysis for Spiralis Energy’s Axial Skelter tidal test rig, delivering a match to experimental data with less than 1.5% deviation. 

Following nearly a year of collaboration, Cape Horn Engineering and Spiralis Energy unveiled the validation results for the CFD program based on real-world conditions from a 6-meter, 1/4 scale test rig deployed at Poole Harbour, UK. The CFD model predicted peak power production, offering key insights for Spiralis Energy’s ongoing tidal energy project.

Cape Horn Engineering’s simulations predicted the skelter’s peak power production at 2.59 kW, while the actual result was 2.50 kW, with adjustments for rig friction putting the two values within a tight margin of accuracy.

“At the rotation rate of 21 RPM, the test rig produces 2.50 kW, and we predicted 2.59 kW. If we take into account the test rig friction, the values are within 1.5% of each other, a very close match indeed. With this validation step completed we can have even more confidence in our prediction that the full-size unit will break the 250 kW threshold,” noted Rodrigo Azcueta, Managing Director at Cape Horn Engineering.

Spiralis Energy and Cape Horn Engineering are now advancing towards the next phase of testing, which will involve a full-scale axial tidal energy converter. The upcoming test will feature a 16-meter-long by 5-meter-diameter Skelter, designed to withstand the harsh winter conditions. The CFD simulations are important for analyzing structural loads and optimizing the hydrodynamic shape for maximum efficiency.

According to Cape Horn Engineering, Spiralis Energy aims to supply up to 11% of the UK’s national grid with its tidal energy technology. 

“The UK has the best tidal knowledge in the world. Our technology can deliver a renewable energy source that doesn’t harm sea life and sits within the circular economy framework,” said Spiralis Energy’s CEO, Guy Levene OBE.

“What makes Spiralis easy to scale is that our units have a modular design to enable them to fit into a standard shipping container for affordable transportation anywhere in the world. It’s really quite straightforward – we’re offering a simple, more affordable, more reliable and sustainable energy solution; our technology simply works.”

The next step for Spiralis Energy is to test two Axial Skelter power-generating screws in Alderney, located in the Channel Islands, which boasts some of the strongest tidal currents in Europe. The seabed ownership in Alderney is expected to support further project development.

Cape Horn’s CFD simulations were processed on a high-performance computing (HPC) cluster using Simcenter STAR-CCM+, a software package from Siemens Digital Industries.

In July, the tidal energy developer Spiralis Energy revealed its intention to bid for a 15-year contract with the UK Government as a part of Contracts for Difference (CfD) 2025 to integrate its technology into the national grid. A site in Wales has already been identified for the project if successful.

Ocean Energy Europe (OEE) appointed two new members to its Board of Directors in early September, of which, one appointee comes from Spiralis Energy.