The newest US subs use shroud protected pump jet propulsor systems, which already minimize acoustic signatures. Especially when it comes to the cavitation noise

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. https://twitter.com/toughsf/status/1024083748407713792?lang=de https://twitter.com/toughsf/status/1024083748407713792?lang=... https://www.researchgate.net/publication/302920496_Numerical_simulation_of_tip_clearance_impact_on_a_pumpjet_propulsor https://www.researchgate.net/publication/302920496_Numerical... https://www.thedrive.com/the-war-zone/31708/veteran-sonarman-explains-why-pump-jets-are-superior-to-props-on-modern-submarines https://www.thedrive.com/the-war-zone/31708/veteran-sonarman... https://www.globecomposite.com/blog/x-factor-columbia-class-submarine-design https://www.globecomposite.com/blog/x-factor-columbia-class-... https://www.sciencedirect.com/science/article/pii/S2092678216302473 https://www.sciencedirect.com/science/article/pii/S209267821...