The UK-based marine technology consultant Cape Horn Engineering has delivered what it described as one of the most accurate and computationally efficient results in a blind tidal turbine validation study, part of a benchmarking initiative funded by the UK’s Engineering and Physical Sciences Research Council (EPSRC) and the Supergen Offshore Renewable Energy (ORE) Hub.
According to Cape Horn Engineering, the study aimed to accelerate tidal energy technology development and reduce modeling uncertainty in turbine design. It combines experimental data from a large 1.6-meter tidal rotor tested at QinetiQ’s Haslar facility under steady flow conditions with and without added turbulence.
The goal was to reduce design conservatism and validate numerical modeling methods for offshore renewable energy applications.
Twelve groups from academia and industry submitted blind computational fluid dynamics (CFD) results using models ranging from low-fidelity methods to high-fidelity blade-resolved CFD. Cape Horn Engineering used Siemens’ STAR-CCM+ code to carry out high-resolution simulations that included full rotor geometry, nacelle, tower, tank walls, and free-surface effects.
Cape Horn Engineering said: “The solutions of CHE-BR-uRANS were found to be very effective with a significantly lower cell count compared to other methods, whilst returning some of the most accurate solutions.”
The firm’s modeling approach fully replicated the experimental setup, including rotating blades, tank boundaries, and water surface deformation. The simulations achieved high accuracy at low computational cost, running in four to five hours on 32-core systems. The average mesh size was around 3.5 million cells, aided by automatic mesh refinement and a hybrid meshing strategy.
Results showed a strong correlation with experimental data. In low turbulence conditions, the average difference in power and thrust coefficients was 0.67% and 2.10%. For elevated turbulence, the average differences were 2.02% and 2.74%. All values fell within the 95% confidence range of the experimental data.
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At submission, Cape Horn Engineering included a full verification and validation (V+V) study, reporting numerical uncertainties below 1% for both key parameters. According to the UK firm, these results ranked among the most accurate and efficient in the benchmark, with other blade-resolved CFD participants often omitting aspects such as tank walls, towers, or free surfaces.
Beyond tidal energy research, Cape Horn Engineering said it applies its CFD expertise to wind energy rotors, floating platforms, wave energy structures, service operation vessels (SOVs), and crew transfer vessels (CTVs).
In October 2024, Cape Horn Engineering completed the first validation of its CFD analysis for Spiralis Energy’s Axial Skelter tidal test rig, delivering a match to experimental data with less than 1.5% deviation.