Re:Ultra-efficient toroidal propeller gets contra-rotating d...
by westurner on Saturday March 16, 2024 @03:16PM
(#39728642)
> Beyond a general promise of better efficiency, agility and maneuverability, Sharrow doesn't dig too deep into how its toroidal blades might improve upon the benefits already inherent in contra-rotating propulsion.
> Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. [...] Planetary gear
> By choosing to hold one component or another—the planetary carrier, the ring gear, or the sun gear—stationary, three different gear ratios can be realized. [3]
> Photos of the drive motor next to a roughly 11-ounce (330 mL) beverage can show just how tiny the Quark motor really is for its power output*
By comparison, a Panther Jeep Wrangler water car has a 4-speed manual "(3,664 cc) 24 valve SOHC V6 VTEC engine which produces 305 HP engine" with an engine weight of 160 kg out of a curb weight of 1,340 kg; and it looks like she drafts about ___ parked and ___ at 38 knots or pulling a waterskier.
Contra-rotating: https://en.wikipedia.org/wiki/Contra-rotating :
> Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. [...] Planetary gear
Epicyclic gearing (planetary gearing) https://en.wikipedia.org/wiki/Epicyclic_gearing :
> By choosing to hold one component or another—the planetary carrier, the ring gear, or the sun gear—stationary, three different gear ratios can be realized. [3]
Other things boats and motors:
[Radial] Axial Flux motor: https://en.wikipedia.org/wiki/Axial_flux_motor
Koenigsigg Raxial Flux motor latest spec from YouTube, originally; 800 HP, 922-lb/ft or torque, under 40kg, but 750A800V=600,000W=60kW
https://www.thedrive.com/news/heres-how-koenigseggs-dark-mat...
> Photos of the drive motor next to a roughly 11-ounce (330 mL) beverage can show just how tiny the Quark motor really is for its power output*
By comparison, a Panther Jeep Wrangler water car has a 4-speed manual "(3,664 cc) 24 valve SOHC V6 VTEC engine which produces 305 HP engine" with an engine weight of 160 kg out of a curb weight of 1,340 kg; and it looks like she drafts about ___ parked and ___ at 38 knots or pulling a waterskier.
Honda J engine: https://en.wikipedia.org/wiki/Honda_J_engine
Panther Jeep Wrangler watercar: https://en.wikipedia.org/wiki/Panther_(amphibious_vehicle)
But Axial Flux motors and geared toroidal propellers do not make MHD drives, which have no moving parts by comparison.
/? mhd drive: https://youtube.com/results?sp=mAEA&search_query=MHD+drive
MHD: Magnetohydrodynamic drive > Typology > Marine propulsion: https://en.wikipedia.org/wiki/Magnetohydrodynamic_drive#Mari...