Preventing inboard roll when turning.

[robse]

Hi
I was thinking: One way to prevent the sub from "leaning into the curve" when you turn, could it not be to give the upper rudder a few more degrees than the lower?
If fx. the lower rudder is at say 20*, then the top rudder could be at say 25*. That would produce in a force trying to roll the hull out of the turning circle, right?

[Rogue Sub]

Its possible but for a

Its possible but for a boat with a good size I think the weight might win out on the turn. On an ohio the boat never leans in the turn. Even when performing high speed maneavers. The thing is just to heavy.

[robse]

Hi NukePower http://www.subcommittee.com/forum/icon_smile.gif
Ok! Wow.. those

Hi NukePower
Ok! Wow.. those boomers ARE big then..
The same thing would maybe then be true for the sub in "Hunt for red october", as this is even heavier. The roll shown when she races through "Red Route One" is then a typical Hollywood stunt..

[Rogue Sub]

More then likely. Although who

More then likely. Although who knows with the size of the upper rudder. I do know they had vibration. Issues at certain speeds due to the water turbulence coming off the sail and slamming the rudder. It also caused their turning radius to go to crap at certain speed. I guess it goes to show, that a bigger rudder istn always a better rudder.

Kevin

[wolfsong]

well, when i run my

well, when i run my typhoon, which is 94 inches long, she heel's over a lot.
i have two independent esc's that are mixed with the rudder.

maybe if i mix the dive-planes (fron't and back) and even control the aft diveplans independently, it might turn with less of a roll..

stefan

[robse]

WOW! You dwarf my 81

WOW! You dwarf my 81 inch OHIO!
Anyway: If I remember correctly, then you have both bow and aft dive planes in the hull it self, right? If you could mix both ends with the (sideways)rudder, then I'm pretty sure you would counter it.
If you try, maybe you'd through a note for us with the results?

Would you have a website with your sub, by any chace?

[pirate]

The main reason for the

The main reason for the roll, as I understand it, is the hydrodynamic forces put on the sail. As the boats longitudinal axis is angled from its straight-line path, the side of the sail gets hit with water (like turning your hand in the wind when you hold it out the car window). This force applied to the side of the sail pushes the boat over into the turn.

On the Typhoon, that sail is huge, therefore a lot more force is pushing it sideways. On the Ohio, the sail is relatively small compared to the size of the boat, so much less force.

This is the whole reason for the sail design on Russian attack boats like the Alpha and Akula. Their sails are angled into the hull shape to make less side area sticking straight up to get hit by those side forces when they turn. And in turn, this reduced force against the boat allows their speed to stay up.

Get rid of the sail and their should be no roll at all.

Pete