Researchers at MIT have demonstrated that wedge-shaped vortex generators attached to a ship's hull can reduce drag by up to 7.5 percent, which reduces overall ship emissions and fuel expenses. The paper , "Net Drag Reduction in High Block Coefficient Ships and Vehicles Using Vortex Generators," was presented at the Society of Naval Architects and Marine Engineers 2025 Maritime Convention in Norfolk, Virginia.
The work offers a promising path toward decarbonization, addressing the pressing need to meet the International Maritime Organization (IMO) goal to reduce carbon intensity of international shipping by at least 40 percent by 2030, compared to 2008 levels. Achieving such ambitious emissions reduction will require a coordinated approach, employing multiple methods, from redesigning ship hulls, propellers, and engines to using novel fuels and operational methods.
The researchers - José del Águila Ferrandis, Jack Kimmeth, and Michael Triantafyllou of MIT Sea Grant and the Department of Mechanical Engineering, along with Alfonso Parra Rubio and Neil Gershenfeld of the Center for Bits and Atoms - determined the optimized vortex generator shape and size using a combination of computational fluid dynamics (CFD) and experimental methods guided by AI optimization methods.
The team first established parametric trends through extensive CFD analysis, and then tested multiple hulls through rapid prototyping to validate the results experimentally. Scale models of an axisymmetric hull with a bare tail, a tail with delta wing vortex generators, and a tail with wedge vortex generators were produced and tested. The team identified wedge-like vortex generators as the key shape that could achieve this level of drag reduction.
Through flow visualization, the researchers could see that drag was reduced by delaying turbulent flow separation, helping water flow more smoothly along the ship's hull, shrinking the wake behind the vessel. This also allows the propeller and rudder to work more efficiently in a uniform flow. "We document for the first time experimentally a reduction in fuel required by ships using vortex generators, relatively small structures in the shape of a wedge attached at a specific point of the ship's hull," explains Michael Triantafyllou, professor of mechanical engineering and director of MIT Sea Grant.
Vortex generators have long been used in aircraft-wing design to maintain lift and delay stalling. This study pioneers the translation of these aerodynamic techniques into hydrodynamic design.
The modular adaptability of the wedge vortex generators would allow integration into a broad range of hull forms, including bulk carriers and tankers, and the devices can synergize with, or even replace, existing technologies like pre-swirl stators (fixed fins mounted in front of propellers), improving overall system performance. As an example case, the researchers estimate that installing the vortex generators on a 300-meter Newcastlemax bulk carrier operating at 14.5 knots over a cross-Pacific route would result in significantly reduced emissions and approximately $750,000 in fuel savings per year.
The findings offer a practical, cost-effective solution that could be implemented efficiently across existing fleets. This study was supported through the CBA Consortium , working with Oldendorff Carriers, which operates about 700 bulk carriers around the world. An extension of this research is supported by the MIT Marine Consortium , led by MIT professors Themis Sapsis and Fotini Christia. The Maritime Consortium was formed in 2025 to address critical gaps in the modernization of the commercial fleet through interdisciplinary research and collaboration across academia, industry, and regulatory agencies.
