Backward x 2 CV Photo

[Terminus]

It's sort of similar to cars. You can have a car with 10,000HP, but if the transmission can't transmit the power, and the tires can't get a grip on the road, you're not going anywhere.

[Apollo11]

Hi all,

ORIGINAL: wdolson

It all makes sense. Another bit they don't talk about is that propellers get less efficient the faster they turn. In air, they get separation at the tips and less of the propeller is biting the air. This is the reason propeller planes can fly faster than the speed of sound in level flight.

In water, I would expect similar dynamics with the water. Spin the propeller fast enough and it ends up churning foam.

It's called cavitation.

Cavitation


Leo "Apollo11"

[Feinder]

I think for my WitP "Final Countdown" scenario, I guestimated 36kts.

It became irrelevant however, because the WitP engine doesn't do anything more than 6 hexes (30kts) anyway (and 36kts would be 7 hexes per phase).
 
I think I'll revisit that this weekend (ie finally finish it).  My PBEM opponents are all going on vacation, so I won't have any turns to do (I really should catch up my AAR as well).
 
-F-

[Dixie]

ORIGINAL: Apollo11

Hi all,

ORIGINAL: wdolson

It all makes sense. Another bit they don't talk about is that propellers get less efficient the faster they turn. In air, they get separation at the tips and less of the propeller is biting the air. This is the reason propeller planes can fly faster than the speed of sound in level flight.

In water, I would expect similar dynamics with the water. Spin the propeller fast enough and it ends up churning foam.

It's called cavitation.

Cavitation


Leo "Apollo11"

And is a BAD thing for aeroplanes[:D]

[MineSweeper]

Here is a photo of a CVN....probaly on trials.....very sharp turn here....

[wdolson]

ORIGINAL: wdolson

It all makes sense. Another bit they don't talk about is that propellers get less efficient the faster they turn. In air, they get separation at the tips and less of the propeller is biting the air. This is the reason propeller planes can fly faster than the speed of sound in level flight.

In water, I would expect similar dynamics with the water. Spin the propeller fast enough and it ends up churning foam.

ORIGINAL: Apollo11
It's called cavitation.

Cavitation

That's the word I was groping for! I had the concept, I couldn't put the word to it though. I tend to be noun challanged at times (drives my SO nuts).

Bill

[herwin]

ORIGINAL: Terminus

ORIGINAL: wdolson

Aren't the CVN-65 Enterprise speeds still top secret?

ORIGINAL: ChezDaJez
Technically, they are still secret. However, I remember a time when she came through our sonobuoy field at high speed. Measured her prop RPMs and computed a speed based on TPK. I had to recompute her speed several times before I believed it. It was "somewhat" in excess of 30 knots.

Chez

I know someone who was on the USS Gearing during Vietnam. He said they were on their way home and were getting topped up by the Enterprise 100-200 miles off the west coast. Enterprise was headed to San Diego and they were headed to Long Beach. He said standard procedure was for the smaller, more nimble ship to pull away first and go to full power. They started running up to 30+ knots and the Enterprise broke away from them and left them sitting there like they weren't even moving. He knew they were doing at least 30 knots and the Enterprise was doing at least twice their speed when he last saw her. He said there was a rooster tail coming off the back taller than the flight deck.

I don't have any way of verifying it, but he never struck me as the sort of person to tell tall tales.

Bill

Except for the fact that he told you the Enterprise was doing 60+ knots. Not possible, even with eight nuclear reactors.

Exactly.