PROP DESIGN - BOATS - APPLICABLE TO PLANES ?

[johnm]

don't know if this has been posted - could be applied to planes ?

 

see link

 

https://youtu.be/MNnB_50Z20I

[AVIDSteve]

It is a very cool idea. If it works in water then there is a chance it would work in air as well. Make it from carbon fiber?

[spenaroo]

[old man emu]

It doesn't look like these toroidal props are worth the effort. These tests are carried out with 3D printed props, but I think the methodology is sound. 

 

 

 

[spenaroo]

they fail my basic sniff test....

 

Is it used in racing?

if the race teams looking for any advantage without care for the budget aren't using it... then its probably marketing hype

[onetrack]

The testing on the water, in the catamaran, and comparing the standard Yamaha props showed some startling performance and fuel economy gains. Remember the engineering team with all the brains in prop design took 10 years to perfect the Sharrow propeller shape, after the original idea was produced.

 

Racing is a narrow field of use, and it's not always accurate to compare what racers use, to what is required for everyday use requirements. I reckon this prop is a winner, and it will soon show up on drones.

[AVIDSteve]

1 hour ago, old man emu said:

It doesn't look like these toroidal props are worth the effort. These tests are carried out with 3D printed props, but I think the methodology is sound. 

 

 

 

They look very flat compared to the boat props. maybe that makes a difference? I know some talented folks with 4d fluid modelling that could tell us

[Old Koreelah]

Small, easily mass-produced plastic props- as used in drones- would be the ideal application.
There has been quite a lot of work done to reduce prop noise and this design seem to tick those boxes.

If this technology follows the pattern set by phones, computers and lots of other consumer goods, soon we might be able to buy a set of motors and props ready to plug into our own designs.

[spenaroo]

52 minutes ago, onetrack said:

The testing on the water, in the catamaran, and comparing the standard Yamaha props showed some startling performance and fuel economy gains. Remember the engineering team with all the brains in prop design took 10 years to perfect the Sharrow propeller shape, after the original idea was produced.

 

Racing is a narrow field of use, and it's not always accurate to compare what racers use, to what is required for everyday use requirements. I reckon this prop is a winner, and it will soon show up on drones.

Maybe....

But they were comparing a 5k aftermarket prop, to a $300 standard prop.
not apples to apples. be interesting to see how it performs against an equivalent aftermarket prop.

was the first performance change we did on Jet-skis. everyone knew going to an aftermarket stainless, multi pitch prop gave a proven performance boost all-round over the stock items. Think of it like testing a composite prop, compared to a wooden prop on a Jabiru.
we all know there is a performance advantage to changing - but plenty still use the wooden option because its good enough.
but using the wooden prop as a benchmark for a new performance prop is pretty silly - except if you want to the big percentage increases for marketing.

Edited March 2, 2023 by spenaroo

[AVIDSteve]

2 hours ago, spenaroo said:

Scrappy's, fan boat prop certainly looks the meaty. Bit short on top end performance but you can climb a wall by all accounts.

[old man emu]

It is interesting that the boaties haven't taken up variable pitch props.

[spenaroo]

9 minutes ago, old man emu said:

It is interesting that the boaties haven't taken up variable pitch props.

It is used in ships and sailing vessels

[facthunter]

You don't need one on a plane till you get above about 120 knots and schneider trophy plane s didn't have them either. Made some takeoffs pretty exciting.  Nev

[AVIDSteve]

27 minutes ago, spenaroo said:

It is used in ships and sailing vessels

yep. though it is really expensive and not terribly good. It didn't make that much difference to yachts to justify the maintenance. Ships though, another story

[spenaroo]

33 minutes ago, facthunter said:

You don't need one on a plane till you get above about 120 knots and schneider trophy plane s didn't have them either. Made some takeoffs pretty exciting.  Nev

Which also brings up a good point,

there already exists shrouded props 

 

[facthunter]

To prevent cavitation, I would think. Water is pretty dense compared with air. That set up would also increase the velocity change in the V(squared) aspect.  Nev

[spenaroo]

yeah, used mostly in low speed, high thrust applications.
the density means that they have a large drag at higher speeds.

so question. with outboards, and azimuth pods being talked about.
is there any aircraft steered by changing the prop position?

Edited March 2, 2023 by spenaroo

[AVIDSteve]

1 hour ago, spenaroo said:

yeah, used mostly in low speed, high thrust applications.
the density means that they have a large drag at higher speeds.

so question. with outboards, and azimuth pods being talked about.
is there any aircraft steered by changing the prop position?

In that thing with blue people.

Also the Americans are doing it I saw recently for VTOL

[RossK]

3 hours ago, spenaroo said:

so question. with outboards, and azimuth pods being talked about.
is there any aircraft steered by changing the prop position?

Vectored Thrust

[Carbon Canary]

V22 Osprey ?

[spenaroo]

thrust vectoring did come to mind. but the idea of a roof mounted engine pod that swivels amuses me.
wouldn't look to dissimilar to existing seaplane design's. imagine it would help with crosswinds

oh could link it to the throttle too, no need for more right rudder

Edited March 2, 2023 by spenaroo

[AVIDSteve]

15 hours ago, RossK said:

Vectored Thrust

Proof that horsepower fixes everything 🙂