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> The MHD drive does not have moving parts, reducing noise and vibration, making it harder to detect via sonar Uh what? Sonar is active detection, using the bo
by bruce343434 3y ago
> The MHD drive does not have moving parts, reducing noise and vibration, making it harder to detect via sonar
Uh what? Sonar is active detection, using the bouncing of emitted sound waves, no? Then I don't see how a silent engine makes it harder to detect via sonar if the signals will still bounce just as hard from the hull.
- andkenneth 3y agoThere is passive sonar too, which is just listening.
- regularfry 3y agoRelevant to this: unimaginably vast amounts of effort have gone into making propellers a little bit quieter so they are harder to hear while still allowing reasonably high speeds. A lot of that is to do with avoiding cavitation at the prop tip, which is a) noisy, and b) very destructive. no prop, no prop noise...
- fl7305 3y agoA submarine is like a ninja. It tries to sneak around undetected. Using active sonar is like placing a siren on your head.
- rkangel 3y agoWhat you are describing is active sonar. The downside of active sonar is that it also clearly reveals your own position. As such, modern submarine warfare relies mostly on passive sonar - very sensitive microphone arrays (sometimes towed behind) to listen for audio signatures of surface and subsurface ships. This means that submarine navies (and anti-submarine surface fleets to some degree) put a high priority on the ability to run quietly. A lot of work is put into things like propellor design to minimise the noise but there's a limit to how far you can go to eliminate cavitation and other noise sources. MHD, which would just be water flowing through a pipe, can potentially be much quieter.