CFD Analysis of WASP Devices

Cape Horn engineering proudly collaborated with AlfaWall Oceanbird AB for CFD Analysis and aerodynamic investigations for their WASP devices. The studied involved various wing concept designs.

The main objective of this study was to determine the overall performance of each prospective geometric WASP design over a range of varying wind conditions, considering the wind speed, angle of attack, and where relevant, flap angles or suction coefficients. A particular focus was to determine the highest lift coefficients for each device.

Forces and moments on the wings were calculated and delivered to AlfaWall Oceanbird AB for further analysis, together with detailed visualisation files of the flow features.

Cape Horn Engineering conducted the analysis by means of RANSE-based high-fidelity CFD to facilitate numerical analysis of the WASP devices in full scale to calculate the aerodynamic forces. The best in class software package STAR-CCM+ was employed, with simulations being set up following Cape Horn Engineering’s best practices, which have been developed through extensive experience in the field. 

Geometric Designs

The first WASP device took the form of a more traditional wing that had a main element and a rotating flap element, each with an airfoil section. Each element had small end plates which overlapped each other. 

The second wing had a much more complex geometry, with a large central part and many smaller surfaces around. This wing had a ’switch flap’ that would only change for a ship sailing on a different tack, thus it was fixed for the duration of the investigation. 

Oceanbird Wing 560

Following Cape Horn Engineering’s CFD analysis, the first WASP device produced superior performance and was selected to be integrated into the vessel design.

The 40 metre high, 14 metre wide, solid wings have been developed through intensive research and development, designed to reduce a ship’s fuel consumption through wind propulsion. The geometric design adjusts the aerodynamics to maximise thrust and reduce fuel consumption (also reducing emissions) by about 10% per unit on optimal routes. The sail’s core is constructed of high-strength steel, with its aerodynamic surface made from glass fibre composites reinforced by 370,000 recycled plastic bottles. 

The hydraulics and electrics are enclosed in the wing machinery house which serves as the integration point with the vessel. The wing sail is a standalone system, that can be installed or retro fitted, engineered for seamless integration with vessel functionality such as power management system and data exchange.

Large Scale Wind Propulsion

The maritime energy transition has reached a symbolic milestone with the first commercial order of rigid sails developed by Oceanbird. The two Wing 560 rigid sails will be installed (retro-fitted) onto an existing ship in Europe, planned for early 2027.

This project is marking the beginning of Oceanbird’s commercial journey toward large-scale wind propulsion, and a decisive step toward the industrialisation of hybrid solutions in maritime transport. The stakeholders in the sector are seeking to combine technological innovation and emission reduction in order to meet international climate goals.

“This is a proud moment for everyone involved. It proves that wind propulsion is not just a concept—it’s a viable, scalable solution for sustainable shipping”, says Amrit Kaur Bhullar, CEO, Oceanbird.s

This first order represents more than a technological achievement, it’s a tangible step toward cleaner, smarter ocean transport. By combining Alfa Laval’s engineering expertise with Wallenius’ pioneering spirit, Oceanbird is turning innovation into action and helping the maritime industry move closer to a net-zero future.

With the Wing 560, Oceanbird takes a decisive step towards making large-scale wind propulsion a commercial reality — and towards realising its vision of truly sustainable shipping for the future.

We investigate carbon-free energy alternatives and design solutions to assist shipping companies with our specialist CFD technologies. For more information, on our Wind Assisted Ship Propulsion (WASP) simulation, see our case study: https://www.cape-horn-eng.com/wind-assisted-propulsion-simulation

Pioneering CFD Simulation workflow

Our pioneering simulation workflow can directly compare the efficiency of wind assisted propulsion, taking into account the most important effects of the WASP devices fitted to the vessel. Both the water flow experienced by the hull at a given vessel speed and the air flow experienced by the hull top sides, superstructure and rotor sails, at a certain wind speed and direction, can be modelled simultaneously in a single simulation.

For more information on our pioneering simulation workflow to directly compare the efficiency of wind assisted ship propulsion (WASP) devices, please see our case study.Wind Assisted Ship Propulsion (WASP)

Cape Horn Engineering are proud to be involved in innovative wind propulsion projects to reduce emissions for the shipping industry, please see our case studies for more details:

Humphreys Yacht Design –FastRig Digital Twin, Smart Green Shipping

Windship Technology  –Assisting new technologies for greener shipping

EcoClipper – Sustainable shipping initiative