The encyclopedia · Engineering & Operations · Technical decision · 2020s
Alfa Laval lays a sheet of air under a hull so the water slides past on bubbles
A fluidic air film under the flat bottom cuts hull drag 50-75%, saving up to 12% propulsion power.
Alfa Laval
the move
A large share of a vessel's propulsion power goes to overcoming friction between the hull and the water, and emissions rules now make reducing it a financial and regulatory priority.
Alfa Laval's OceanGlide combines air lubrication with fluidics to create an even air layer over the entire flat bottom of a hull, controlled and optimized as the ship sails.
The result is a 50-75% reduction in drag and propulsion-power savings of up to 12%, with lower fuel use and CO2 — and it can be fitted to existing ships as well as newbuilds.
why it works
- It targets the dominant energy drain — hull friction — rather than the engine.
- Air costs almost nothing to generate and has no moving parts to wear.
- An optimized film cuts drag across the flat bottom, not just at one point.
- It improves carbon-intensity ratings that regulators now require for large ships.
what transfers
You can beat friction with a bearing made of nothing — the cheapest lubricant is a layer of gas you generate on board.
what came after
OceanGlide is marketed as a retrofit or newbuild option, and operators report reliable fuel savings of up to 12% plus improved EEXI and CII ratings as IMO's carbon-intensity regime took effect from 2023.
references
- Boost fleet efficiency with Alfa Laval's OceanGlide air lubrication system
- Computational analysis of air bubble-induced frictional drag reduction on ship hulls
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