If you could demonstrate, prove or explain why water speed should
be identical along each side of the rudder

water speed does not have to be equal or greater or less. This can be a bit
confusing because "bernoulli" is often -- though erroneously -- given as the
reason sails/wings have "lift".

It might be a bit easier to remember that for the rudder to be pushed one way,
it (the rudder) must push water the opposite way. If the water is not
deflected then there is no force on the rudder.

I mentioned Feynman because some clowns on this ng (I speak of schlackoff and
jeffies and others) go ape squat when I make a statement, absolutely insisting
that if I say it I must be making it up (I make up nothing) will argue for
weeks (like sophomores in college wasting afternoons in the student cafeteria
as they consider their fourth or fifth major) to prove because they didn't know
something prior, no one else could have either.

Feynman, a serious physicist, got sick and tired of arguing with the 4th major
sophomore types and made a movie of the situation, showing clearing exactly
what was expected. I used Feynman's name to shut up schlackoff (fat chance)
and jeffies (who became quiet once he goggled the name Feynman).

I mentioned the whole issue because I have met boaters who, when the complained
about troubles backing up their ruddered boat, had unscrupulous marinas try to
sell them a multi-thousand dollar "solution" to the problem by "moving the prop
closer to the rudder for better control". Which won't work, of course.

On Sun, 28 Mar 2004 13:47:47 GMT, L. M. Rappaport
wrote:

From: "Derek Rowell"


oops! He's a professor there!


Not surprising that he's offering an opinion on fluid dynamics.
While supersonic flow is studied more by aero engineers these
days, slow speed fluid flow is the province of mechanical engineers.

Take a look at "Fluid Mechanics" Fogiel/Cimbala
for an example.
Cimbala is Prof of Mech Eng at Penn State.

Brian W

brian, you have been suckered. that was not derek rowell professor of stress
analysis in Mech Eng, but rather someone pretending to be him. NO professor at
MIT would write what that clown wrote. None. He would be laughed at the rest
of the staff, and some disgruntled student would report him to the president
for disciplinary action. Who would pay money to "learn" something that is
known so wrong by the entire staff?

L. M. Rappaport
wrote:

From: "Derek Rowell"


oops! He's a professor there!


Not surprising that he's offering an opinion on fluid dynamics.
While supersonic flow is studied more by aero engineers these
days, slow speed fluid flow is the province of mechanical engineers.

Take a look at "Fluid Mechanics" Fogiel/Cimbala
for an example.
Cimbala is Prof of Mech Eng at Penn State.

Brian W

supersonic flow

supersonic flow was mentioned by no one in this context, and is not important
to note in this context.

On 28 Mar 2004 02:40:34 GMT, (JAXAshby) wrote:

[snip all but the important stuff from schlackoff's post]

==========================================

Time to give it up Jax, you're busted.

Fact is Feynman was right, BUT,

[Sprinkler Heads] [not equal] [Rudders]

Prop flow over rudder in reverse is small but it's there.

As a result It exerts a force against the rudder, but the effect is
small enough to be negligible for all intents and purposes.

[Small Negligible Force] [not equal] [No Force] however.

wayne, are you really saying that while Feynman was right regarding the forces
involved in water flow, he wasn't right when water flowed over a rudder?

Interesting. Should you be able to show that you can beat sher to the next
Nobel prize in physics. Hurry.

Time to give it up Jax, you're busted.

Fact is Feynman was right, BUT,

[Sprinkler Heads] [not equal] [Rudders]

Prop flow over rudder in reverse is small but it's there.

Fact is Feynman was right, BUT,

Prop flow over rudder in reverse is small but it's there.


nobody said there was no flow -- there is -- but it is stated that the total of
the forces on the rudder are zero. that's a fact of physics. accept it or
not. your choice. look like intelligent or a Luddite. your choice.

It exerts a force against the rudder,

why is that? Please explain in detail, as the physicists disagree with you.
If you are right, you stand to make a fortune on the Nobel prize money alone.

On Sun, 28 Mar 2004 00:35:03 GMT, "Derek Rowell"
wrote:

.....
That's not how we do business in science and engineering. We calmly look
at a situation, make hypotheses and conjectures and then think of a set of
experiments to disprove or prove our ideas. We invite others to disprove
our theories, and rejoice when they do, because we learn something.


From: "Derek Rowell"




Derek,
In hopes you didn't give up on this list altogether, here's a little
puzzle you might enjoy. There is a demonstration of the Feynman
sprinkler puzzle somewhere at MIT.

What simple modification could you easily introduce to the nozzle in
order to demonstrate a force due to suction as well as that due to
pressure? Perhaps I could hint that it would augment the force? :-)

Brian W

On 29 Mar 2004 03:27:38 GMT, (JAXAshby) wrote:

It exerts a force against the rudder,

why is that? Please explain in detail, as the physicists disagree with you.
If you are right, you stand to make a fortune on the Nobel prize money alone.

================================================== ==

If flow deflection takes place (rudder at angle to flow), a force is
exerted. Old news to everyone, Nobel prize not likely.