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


Derek, you may be able to show a "force" being exerted on the rudder in this
way.
However, connect that rudder to a boat, and although this "force" may be
sufficient to pull that rudder further over (seen that), it will, EG almost
always, never be sufficient to act as a steering force for the boat to any
degree that is useable.
My apologies if I don't launch into some longwinded scientific dissertation.

Shen

You caught me again! Damn! Yep, I'm the fraudulent plumber

I simply gave you a simple experiment to do

your silly "experiement" didn't hardly match up with Feynman's. who are we to
believe?

Derek, or perhaps as a courtesy I should say Professor Rowell,
why would you think a physics graduate (as described)
with a reading knowledge of some Feynman stuff
be impressed by the opinions of an MIT prof of Mech Engineering?

Don't be discouraged. People try to avoid the crack pots as far as
possible, and still get lots of value here.

Brian W

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

OK. You caught me again! Damn! Yep, I'm the fraudulent plumber who can't
read from yesterday. I spent a long time fabricating that email address.
It gives my ego a huge boost. Just to prove that the address is
fraudulent - go to the MIT web site (http://web.mit.edu) and do a "people"
search on my name.

I simply gave you a simple experiment to do - and you attack me
personally. (Do it yourself, and draw your own conclusions - takes about 5
minutes)

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.

That's the end of this discussion. No more!

I simply gave you a simple experiment to do - and you attack me
personally.

because you are a lying sob, a cyber clown.

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, eh? *you* AND Feynman?

you are a fraud, dude.

and rejoice when they do, because we learn something.


*if* that were true, you would have "learned something" several decades ago.
This is not new stuff, though it is obviously foreign to you, oh great janitor
at MIT.

On 27 Mar 2004 23:50:22 GMT, (JAXAshby) wrote (with
possible editing):

derek, your fricken fraud. I just now noticed your fiticious email address of
mit.edu. NObody from MIT would write what you wrote.

geesh, dude. get a life.

From: "Derek Rowell"


oops! He's a professor there!
--

Larry
Email to rapp at lmr dot com

Jax,

I accept that 'suction' will not create a force. Any forces come
from the new exit momentum of a fluid (point the hosepipe where
you will . . . .) presumably this was Feynman's case. I haven't
met the guy, Fine. The effect is easy to observe on VTOL
aircraft. They suck from forward, but don't have to lean their
jet output forward to cancel any 'sucking' force when hovering
static. Here we agree.

I'm looking for an explanation of the phenomenon I thought I had
seen on a very old tug, also on an old trawler, neither of which
had any significant prop walk in astern, though both had big
props. The phenomenon was that rudder deflection with engine in
reverse (boat static) could be used to create a little yaw. The
explanation given to me was that 'flow over the rudder' created
this effect. I rationalised this explanation (perhaps wrongly) by
assuming the rudder changed the momentum of the water ingested by
the prop. ie, water speed along the inside of the rudder is
faster than water speed over the backside of the rudder; a very
simple 'hydrofoil in free stream' effect.

As a result of this thread I am re-examining this assumption and
my observations.

Now, it could be that my observations were wrong, and the
phenomenon did not occur. I was, perhaps, seeing yaw caused by
another effect - inertia due to a previous action maybe. And
perhaps my observations were clouded by the pre-conception
planted in my mind that it worked. But I'm afraid your
explanation (paraphrased very crudely) 'you're wrong because
Feynman says so' doesn't help me. Also, Derek Rowell's experiment
shows that there is some effect which needs explanation - rather
than dismissal.

If you could demonstrate, prove or explain why water speed should
be identical along each side of the rudder (which I assume would
porve that pressure on each side is identical), irrespective of
rudder deflection, when the boat is static with engine in
reverse, I'd happily accept your thesis that rudder has no
effect. As in many of these cases, it may help to explain this
for an extreme case; a balanced spade rudder at 70degrees
deflection close to the prop?

If the rudder suffers some net pressure, then I'd like to
understand what mechanism cancels it.

Can you help without appealing to higher authorities?

JimB

maybe *some* derek rowel is a professor at MIT, but the clown posting as he
here most definitely is not. NO professor at MIT would write the tripe he
wrote.

hell, you know the poster is a fraud. he both claims to be a Mechanical
Engineer and an expert in fluid flow.

the poster claiming to be derek rowell is probably the janitor. the guy who
learned his "fluid flow" knowledge cleaning toilets.

derek, your fricken fraud. I just now noticed your fiticious email address
of
mit.edu. NObody from MIT would write what you wrote.

geesh, dude. get a life.

From: "Derek Rowell"


oops! He's a professor there!
--

Larry
Email to rapp at lmr dot com