Whiteboard Mondays 09: Kort Nozzles

Did you think that the ring around some propellers is there to protect your fingers? Not really :) Have a look at our video where Marek explains this mystery!

[@danatompkins4385]

I would love to see a video on how the Kort Nozzle creates more drag at higher speeds. It seems like there would be a way to get around any drag created but the nozzle structure itself if that is whats causing the drag. I would love to hear an explanation on this. Thank you for the video.

[@xenofonkampourakis8757]

Congratulations, excellent presentation. Regards from Greece!!!

[@LiveThatAdventure]

Is it similar with ducts on drones? I think the force is magnified because water is much more dense, but I think it is the same effect.

[@swobodamarek]

Yeap! Good catch! Exactly the same. I would say the pressure separation at the tip of the blade would be the primary benefit in aeronautical applications while with water the "hydrofoil" effect is listed as the primary factor. There is also a different type of Kort nozzles, not discussed in the video, which creates increased pressure region around the propeller to minimize the cavitation and these nozzles don't apply to aeronautical solutions.

[@emanuelepertile7648]

Yes but keep in mind that having a ducted propeller , which trust is direct for example upwards in a moving fluid like air can induce some unwanted effects. Imagine that you are moving at a slight angle in this fluid, the air coming from in front of the ducted propeller will be faster therefore having a lower pressure which creates more lift, but , the air getting sucked in fronte the propeller coming from behind the propeller will be slower because it will have to move against the fluid the ducted propeller is moving in therefore you will have higher pressure resulting in less lift. Consider that combined with the effect of the frontal higher lift andò you get yourself a very nice(noto really) tilting momentum which Tries to readjust tour asset to a position in which the fluido enters the propeller at more or lesse the same speed from Every direction. With multirotors you will have some chance because of differential thrust bit otherwise you can't gi very fast😅 For examples search that gold project known ad the American saucer it was this weird UFO Mike contraption which was great bit in real life couldn't go fast at all😂

[@edwinajames8991]

thanks for the video, very helpful! ... does the increased pressure differential have implications for cavitation?

[@BHARGAV_GAJJAR]

Damn I might need a bigger board !

[@jhonathancirosalasfernande6628]

Thanks!

[@taxpayer239]

Wow...thats cool....I wondered what that was about. The principal as wing air flow physics.Water is dense and heavey, but like air it has " fluidity" meaning it has no shape or form. It takes the form or shape of what ever container or medium its in.I understand what your saying completely, but I would have a hard time explaining that to someone!!..thanks !!

[@emirotuzucon]

Thanks

[@amphi7967]

You welcome, Emir! Let us know what you are using the kort nozzles for!

[@emirotuzucon]

@@amphi7967 to increase the thrust. But if you use it in fast boats, it will lose the effect of itself and leads to power loss.

[@tombouie]

Thks

[@amphi7967]

Sure thing, Tom! Let us know what you are using the kort nozzles for!