Subject: push vs pull vis a vis rudders
From: (JAXAshby)


So, Jax, from this, I see you didn't understand another simple, concise comment
on the subject.
Shame you don't have any practical experience to back up and explain your
typical pontificating.
EG wanna try the inboard/outboard turning prop subject ..... didn't think so

Shen
schlackoff, knock it off. you gibber worse than a gas station attendant
trying
to claim degree from MIT.

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

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 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.

******************If****************** flow deflection takes place (rudder at
angle to flow), a force is
exerted.

*IF* is the operative word. The question is why do *you* believe there is
deflection? The physicists don't believe that. Why do you?

Wayne.B wrote in message
...
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.

Wayne,

I can imagine a description of flow over the rudder which would
meet Jax's flat (and rather unhelpful) statements, and also
square with the obvious deflection that must occur just before
entering the prop. Whether it's realistic or not is another
matter.

Perhaps water approaches the propeller via the deflected rudder
through an Ess bend. ie, water approaches a point about a third
of the way from the tip of the deflected rudder (lets call it the
stagnation point). From one side of this point, water idles off
at a steep angle to round the rudder tip, doing a hairpin bend to
run back to the prop. From the other side the water moves quickly
along the rudder surface to the prop.

Well, it's a thought. I'm off to play with bits of card and wire
to repeat Derek Rowells experiment, so perhaps I should add a few
burning fag ends to the picture?

JimB

Wayne.B wrote:

Take a look at flow patterns through props some time. You're
assuming that all the flow past the rudder (when on the suction
side) is parallel to the keel (center) line, as it *basically* is
on the discharge side.

The intake side of the prop, however, has a cone-shaped intake
pattern, with the prop at the apex. If the rudder is at an angle
to the centerline, flow will take the path of least resistance,
and to the extent that there is impact pressure on the rudder side
with the highest aspect ratio, this will just cause
disproportionate flow around the other side, increasing impact
pressure on that side, until an equilibrium is reached. Once past
the rudder, the flow resumes its 'along the centerline' flow, so
there is no net deflection, and all 'thrust' is parallel to the
centerline.

Keith Hughes

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