View Single Post
Old 03-08-12, 11:33 PM   #6
Sailor Steve
Eternal Patrol
 
Sailor Steve's Avatar
 
Join Date: Nov 2002
Location: High in the mountains of Utah
Posts: 50,369
Downloads: 745
Uploads: 249


Default

Quote:
Originally Posted by TorpX View Post
I don't believe this is true for WW II boats. Modern nuc subs are slowed by the bow wave on the surface, but most of the WW II boats were designed for surface travel. At least this is what I've read.
He was talking about running on batteries. It's true that WW2 subs were designed for surface running, but hydrodynamic drag is what it is. If surface running on batteries changes anything, it will be for the worse.

One of the effects of wave propagation is that as speed increases the bow tends to lift. The bow wave cuts under the ship and the ship is forced to climb a hill made of water. The faster the speed the steeper the climb, the more power required and the more fuel used. At four knots there won't be much difference, at eight a little more. All I was trying to say is that using batteries on the surface won't increase the range. On the other hand running decks awash doesn't help even though the hull is submerged because that close to the surface the hull creates a boundary layer that tends to cause even more drag. This, coupled with the drag from the sail, just makes it worse. It's a no-win situation.
__________________
“Never do anything you can't take back.”
—Rocky Russo
Sailor Steve is offline   Reply With Quote