3 ms·
The problem with hydrofoils is that they don't scale up very well. Practically all larger designs were always gas turbine powered to even be able to supply enou
by moffkalast 3y ago
The problem with hydrofoils is that they don't scale up very well. Practically all larger designs were always gas turbine powered to even be able to supply enough power for initial liftoff and guzzled kerosene at laughably unprofitable rates. Much like ekranoplans and hovercrafts they didn't really prove to be economical in the long run.
This smaller bus-sized version might genuinely be at the limit of what makes sense with current battery and motor tech.
- bagels 3y agoWhy is this? Is it because the boat mass doesn't scale linearly with surface area?
- moffkalast 3y agoI wish I could give a good explanation, but from what I understand it's more down to fluid dynamics than usual intuition would dictate. The resistance curve [0] has unusual peaks where resistance is highest based on wave creation and interaction with the hull length [1], which interestingly makes longer ships able to reach higher cruise speeds more efficiently (why container ships are as large as they can be), but it also increases these maximums that need to be passed, making transitioning to planing even harder. Due to these factors you'd probably need beyond 8x the engine power to plane/foil with a 2x larger ship. [0] https://amarineblog.files.wordpress.com/2017/06/basics-ofshipresistance-16-728.jpg?w=485&h=364 https://amarineblog.files.wordpress.com/2017/06/basics-ofshi... [1] https://calconcalculator.com/wp-content/uploads/2021/12/image-53.png https://calconcalculator.com/wp-content/uploads/2021/12/imag...