Researchers have demonstrated a practical path to lowering the aerodynamic drag of modern sailing vessels. The finding comes from Chalmers University of Technology and is gaining attention for its potential to cut fuel use and emissions in a sector under pressure to decarbonize.
Ambitions to halve carbon emissions from global shipping by 2050 are part of wider efforts to meet climate goals agreed in the Paris Agreement. Some observers have proposed turning certain cargo ships into sail-assisted craft, an idea that blends traditional wind power with today’s propulsion technology. Modern turbo sailing ships often resemble upright tubes or pylons that can be powered by internal combustion engines rather than classic canvas sails. A key hurdle remains, however: their own aerodynamic drag can limit acceleration and overall efficiency, even when hybrid systems are in play.
Swedish researchers have now introduced an approach that targets this drag specifically. Drawing on aerodynamic insights from aviation, they report a measurable 7.5 percent reduction in drag for ships employing the new technique. The improvement translates into better energy efficiency and lower fuel burn, especially when the system is used in conjunction with hybrid propulsion configurations.
The heart of the method lies in the Coanda bonding effect. This principle describes how liquids and gases tend to follow curved surfaces instead of being pushed away when they encounter a convex shape. In ship design, a major source of drag is the square, protruding aft area of a vessel’s superstructure that rises above the deck. The researchers’ design creates a convex profile around this zone and introduces what they call jet slots to channel high-pressure air in a controlled way. The result is a smoother flow of air around the ship and a notable drop in pressure differences that would otherwise slow the vessel down.
By guiding air more efficiently around the superstructure, the fabric of the hull experiences less resistance. This effect is not a mere theoretical curiosity; it acts directly on real-world performance, making vessels faster at given power levels and more economical to run on long voyages. The trajectory of a typical voyage from the Middle East to East Asia illustrates the potential impact. For a large oil tanker traveling from Saudi Arabia to Japan, modeling suggests a fuel-burn reduction in the vicinity of ten metric tons over a standard operating cycle. That is a meaningful gain in a trade where margins and reliability matter as much as speed.
Experts emphasize that the technique is compatible with existing ship configurations and can be integrated with current hull forms and deck layouts. It does not require a complete redesign of the superstructure, but rather a targeted adjustment to how air flows around critical corners and edges. In practical terms, this means retrofits could be possible on some ships without interrupting key operations. The concept also opens avenues for further refinement, such as tuning the jet slots for different ship sizes or adjusting the convex surface to suit various weather and sea states. The collaboration between engineers, naval architects, and industry partners is seen as essential to moving from lab measurements to sea trials and eventual commercial use.
Beyond ships presently in service, the approach holds promise for new vessels engaged in ambitious routes where fuel costs and emissions are tightly watched. In the maritime sector, even incremental gains in efficiency compound over long voyages and large fleets. As nations and firms map out decarbonization roadmaps, innovations like the Coanda-based drag reduction offer one more lever to balance reliability, performance, and environmental responsibilities. The researchers continue to refine their models and test new configurations, aiming to quantify benefits across different ship types and operating profiles. Attribution: Chalmers University of Technology and collaborating researchers report on this method and its potential implications for shipping efficiency.