Small sport boats usually operate way above hull speed in the the far non-linear region so an extra ten percent thrust will result in a far non-linear increase in speed. I'd believe an extra 15% of thrust would only make it 2% faster.
Really small boats with really huge engines can push quite a bit past hull speed at ultra low efficiency, and that's the only numerical stats they're providing in the article, which is interesting. I wonder if performance is just as high at low speeds, below hull speed, where most cargo ships operate and all the marketing greenwashing is occurring.
Hull speed is not "supersonic" but its a similar enough to rhyme concept, where the boat has a tough time pushing up or thru its own bow wave, sort of, so the max speed of a boat is mostly related to its length. Oddly enough the hydrodynamic variables all cancel out or whatever such that mostly all that matters is wetted hull length for hull speed. You'd superficially guess something like hull depth would matter or width or shape kind of like the stall speed of an airplane wing depends on its shape, but no, ships hull speed almost entirely depends on the wetted hull length. Just a weird hydrodynamics thing.
Maybe an air craft carrier with 10 times the power could go 5% faster, but it would take 100x the power to get an AC carrier up on plane like a ski boat.
However engines are roughly linear in displacement vs power output. A 15% increase in thrust would mean you can reduce the displacement of the engine by 15% and maintain the same speed. This would be compounded by the weight savings, smaller fuel tank, etc.
However, I think there is a far less than 15% increase in thrust, and due to the super-linear loss of efficiency at the top end to get a 15% increase in efficiency for the same output level might only require a 3% or so increase in thrust at that output level.
Really small boats with really huge engines can push quite a bit past hull speed at ultra low efficiency, and that's the only numerical stats they're providing in the article, which is interesting. I wonder if performance is just as high at low speeds, below hull speed, where most cargo ships operate and all the marketing greenwashing is occurring.
Hull speed is not "supersonic" but its a similar enough to rhyme concept, where the boat has a tough time pushing up or thru its own bow wave, sort of, so the max speed of a boat is mostly related to its length. Oddly enough the hydrodynamic variables all cancel out or whatever such that mostly all that matters is wetted hull length for hull speed. You'd superficially guess something like hull depth would matter or width or shape kind of like the stall speed of an airplane wing depends on its shape, but no, ships hull speed almost entirely depends on the wetted hull length. Just a weird hydrodynamics thing.
Maybe an air craft carrier with 10 times the power could go 5% faster, but it would take 100x the power to get an AC carrier up on plane like a ski boat.