Interesting propeller shape. Any idea?

[Bubblehead Nuke]

Originally Posted by Dr.Sid

So that small prop actually used ? On 688 class ?

This is not really a prop... and it does not do what you think is looks like it is doing.

Yes, it is there, and it is probably used on all 688's now. I can not tell you what it was called as it was (and for all I know still is) a classified item. I know our boat was testing working hardware of the original concept design. I can tell you for a FACT I know what it is, what it is there for, and how it works.

The reason for it goes beyond the scope of a sub sim.

[Dr.Sid]

Well now that we started .. who cares about the sim .. I just want to know what it is good for :rotfl:
Looks like another google night.

[Bubblehead Nuke]

Good luck on the search, this is a black topic.

[Dr.Sid]

Yeah .. it's perfectly allright .. I guess we all respect your oaths.

But I have found something. It's all matter of good search terms.

http://ci.nii.ac.jp/naid/110003873027/en

You can get whole PDF paper but it's mostly in japanese. Still the abstract says it all.

But it took me an hour.

[Bill Nichols]

Originally Posted by Dr.Sid

Yeah .. it's perfectly allright .. I guess we all respect your oaths.

But I have found something. It's all matter of good search terms.

http://ci.nii.ac.jp/naid/110003873027/en

You can get whole PDF paper but it's mostly in japanese. Still the abstract says it all.

But it took me an hour.

Great find, well worth the hour it took you.

[Bubblehead Nuke]

Originally Posted by Dr.Sid

Yeah .. it's perfectly allright .. I guess we all respect your oaths.

But I have found something. It's all matter of good search terms.

http://ci.nii.ac.jp/naid/110003873027/en

You can get whole PDF paper but it's mostly in japanese. Still the abstract says it all.

But it took me an hour.

Interesting abstract.....

I can not confirm nor deny....

[Task Force]

Non sence... The little prop powers the turbo drive that lets it travel at the speed of sound underwater...:rotfl:

of course... The article could be right... I guess the large prop helps it stay quiet, and produce speed effectivly because of its shape... and maby the smaller prop does like the artical says... or is some kind of thing to fool a distroyers listening equipments... to make it sound faster than it is... could also be there to fool homeing torpedos... (noise fools them...) may add to its speed when staying quiet... but im just guessing... I could keep speculating...

[goldorak]

Originally Posted by Bubblehead Nuke

Good luck on the search, this is a black topic.

Something to do with reducing cavitation and therefore enabling a sub to have higher speed at or near the surface ?
Just my guess.

[Castout]

Originally Posted by Dr.Sid

As the propellers go, nobody who knows will tell you.

But on Microsoft maps there was picture some time of Ohio propeller. That propeller was for sure designed for stealth. And it is based on ww2 design, where the tip of the blade is extended back, so it looks like huge 7 bladed swastika.

I have never seen something like this though. Not on any model, any picture, not in any books on submarine design.

But it totally gives sense. Limiting part of the screw is the propeller tip. The tip moves at maximum possible speed (not to cavitate) and the rest of the blade moves slower then it could. The second screw could rotate faster with same tip speed .. and accelerate that not so well used middle part of the propeller disc. It would be something like propeller which tips moves slower then the blades (ultimate dream of any propeller designer).
Also the second propeller could be counter-rotating, which could help even more. It does not look so from the picture, but AFAIK it is DW's limit and DW can't do counter-rotating propellers.

So it would improve effectiveness - it could achieve better acceleration at same power, and it would need less power to achieve same acceleration. That means it could be even more silent.

Sure it would complicate a gearing, I mean a lot.

Any link for that swastika like prop?

Originally Posted by Bubblehead Nuke

This is not really a prop... and it does not do what you think is looks like it is doing.

Yes, it is there, and it is probably used on all 688's now. I can not tell you what it was called as it was (and for all I know still is) a classified item. I know our boat was testing working hardware of the original concept design. I can tell you for a FACT I know what it is, what it is there for, and how it works.

The reason for it goes beyond the scope of a sub sim.

So it's not meant to add additional push force lol

[Dr.Sid]

Ohio propeller (and more):

http://images.google.com/images?hl=c...ropeller&gbv=2