> Instead, the battle of submarine silence has mostly revolved around obscure technical problems of fluid dynamics, since one of the loudest noises made by submarines is the cavitation around the screw. I don't know if this is true today, but at least years ago the low-noise design of the screw on modern US submarines was classified, and so the screw was covered by a sheath whenever a submarine was out of the water.
I wander if they are Toroidal or "tipless" propellers? They create less turbulence and cavitation.
The newest US subs use shroud protected pump jet propulsor systems, which already minimize acoustic signatures. Especially when it comes to the cavitation noise from propeller tip vortices, which is what Toroidal props are fixing for "open" propeller designs.
> Instead, the battle of submarine silence has mostly revolved around obscure technical problems of fluid dynamics, since one of the loudest noises made by submarines is the cavitation around the screw. I don't know if this is true today, but at least years ago the low-noise design of the screw on modern US submarines was classified, and so the screw was covered by a sheath whenever a submarine was out of the water.
I wander if they are Toroidal or "tipless" propellers? They create less turbulence and cavitation.
https://en.m.wikipedia.org/wiki/Toroidal_propeller
Previous posts on HN:
> Toroidal propellers turn your drones and boats into noiseless machines
https://news.ycombinator.com/item?id=34571282
> Sharrow MX-1: Tipless propeller
https://news.ycombinator.com/item?id=33949895