Rowley's 400 and the Magic Tube , hijacked version .

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Well, actually if you read it correctly, both theories apply and they do explain it to a certain degree. Bernoulli's principles do apply as does the Newtonian theory. The jist of the article is:

1.) Over simplified representation of Bernoulli's principle (as it applies to air foils) as seen in many texts is wrong,
2.) Bernoulli's principle when properly applied explains lift,
3.) Bernoulli's principle is compatible with Newtonian theory in these instances.
 
Re: Rowley's 400 and the magic spray tube .

L.A.B. said:
84ok said:
Rohan said:
Can someone elaborate on what is 'US silencing' ?
Click to expand...

the black cappers 75
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That seems doubtful, as black cap silencers had already been fitted to the 850 Mk1A and 2A models sold elsewhere for more a year before they became the 'standard' for '75 in the US, although we know some Mk2A models were sold in the US, the vast majority were Mk2-with peashooters?
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good bet what i said is incorrect, as it applies to the "us silencers" involved or related to this thread,

i was only aware of the black cappers being referred to as "us silencers",

turns out there was/is more to the story ..i think
 
So are lower or notched spray tubes used to lean or richen low rpm mixture. Some point to extra pop of 2 stroke intakes to need Leaner mix via a notched spray tube while others point to slower 2 stroke intake draws needing shorter or notched spray tube to Richen up initial throttle up from low rpms. I know in my 4 stroke Norton a lower or notched spray tube Richens initially. Notched spray tubes and accelerator pumps are known to help low down response by enRichening but Nortoneers here say its to lean the initial throttle snap. hobot and rest of the world thinks low or cut out spray tube EnRichen > while accessnorton experts state the opposite. sheeze. Its is well known in science history to toss out results that go against those basing a career-funding on some belief - till they die off and better facts taken into account. HIjacked or being set straighter???

The Differences in Two-Stroke and Four-Stroke Carbs
The difference between a two-stroke and four-stroke engine is intake velocity. Two-stroke engines
have lower velocity so the needle jet has a half-moon shaped hood protruding into the venturi to
produce a low-pressure area that aids in drawing the fuel up through the needle jet. Four-stroke
carbs need to atomize the fuel more so than a two-stroke carb because so much of the fuel shears
along the intake port and separates from the mixture stream. Four-stroke carbs have more jets
and finer adjustment screws, plus they usually are equipped with an accelerator pump. A typical
state of the art four-stroke carb is the Kehin CR.
The latest trend in two-stroke carbs features a pump that sprays fuel into the venturi from 1/4th to
3/4th throttles. In the past, carb manufacturers made jet needles that attempted to compensate
for the natural lean condition of the mid-range but that compromised the jetting at full throttle.
The auxiliary pumps are powered by electricity supplied by the alternator (about 5 watts) and
controlled by either a throttle position or an rpm sensor.
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https://www.google.com/url?sa=t&rct=j&q ... 1572,d.aWw
 
Review the remarks yourself, which I think you concur with and label as highjacking - that imply or state short or cut back spray tubes are installed to lean initial throttle opening. All the references I can find + my meager experience say shorter or cut back spray tube give more initial richness. Every time I post a cut back tube reference or influence of flow vs pressure changes I get barked at - as disagrees with reasoning of seasoned barkers. Shooting at the messenger does not change flow physics. I say both 2 & 4 stroke engine intake pressure changes more before air speed does on initial throttle lift. Would taller or short tube spill fuel out more fuel sooner?

Ludwig do you think or know if shorter or cut back spray tubes is for richer or leaner effect?
Do you know which spray tube gave the 850 life & quiet enough to get sold?
Do you know if this was d/t richer or leaner initial throttle mixture?
Please post a reference to support cut out spray tube are to lean initial conditions.
 
hobot said:
Review the remarks yourself, which I think you concur with and label as highjacking
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and this from the man who hijacks others' threads (needing air for one) with his endless back and forth bantering chit chat with rohan
 
Re: Rowley's 400 and the Magic Tube .

84ok said:
i'm interested in the "Press on board" part you mentioned?
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I've seen a video taken inside the passenger cabin, where the world outside the windows turns turtle and back,
and the drinks on the tables don't even slosh.

Maybe there was more than one rollover then ?
Although I doubt it, the pilot seemed very chastened....

But we divert and hijack, very much so.

Thanks to Snorton74 for READING the NASA spiel, they obviously know how wings work...
 
84ok said:
hobot said:
Review the remarks yourself, which I think you concur with and label as highjacking
Click to expand...

and this from the man who hijacks others' threads (needing air for one) with his endless back and forth bantering chit chat with rohan
Click to expand...
Oh 84ok. Since this one is already hijacked...
I disagree with your sentiment. I have found hobot's sometime verbose postings to often contain pearls of wisdom or links to answer an as yet unasked question and as such is a positive contributor to the 'Air' thread. Yes, like the rest of us, he may not be correct all the time but unlike rohan he does not use bellicosity to disguise ignorance. Perhaps live and let live or click the troll button - it really does work (me being a softie, let them out again but they don't seem to change each time so back under the bridge they go). :D
Ta.
 
Ugh youknowwho that had to modify prior firm loud remarks about Bernoulii on wings or spray tubes at low initial flow rates hahahehehehohoho off to the funny farm. Anywho was incentive to me to learn more about spray tubes to retain an opposite comprehension of cut outs. I resent implication me-hobot is somehow trying to mislead anyone. Life is mean and short enough I just like sharing the highs and ready to change my mind on better data.
 
needing said:
Perhaps live and let live or click the troll button - it really does work (me being a softie, let them out again but they don't seem to change each time so back under the bridge they go). :D
Click to expand...

Thats funny - when folks can't even quote or read science, and someone points this out they get lambasted...
 
hobot said:
Ugh youknowwho that had to modify prior firm loud remarks about Bernoulii on wings or spray tubes at low initial flow rates hahahehehehohoho off to the funny farm. Anywho was incentive to me to learn more about spray tubes to retain an opposite comprehension of cut outs. I resent implication me-hobot is somehow trying to mislead anyone. Life is mean and short enough I just like sharing the highs and ready to change my mind on better data.
Click to expand...

You were totally wrong on wings theory, IF you had read that Nasa stuff. !
Perhaps you still don't understand ?

Worth pointing out too that for DECADES carburettors didn't have idle jets, it was entirely Bernoulli workings...
 
I've played with hoods or shields on mikuni needle jets and not really got much for results. I guess unless everything else is spot on the other circuits over ride what I was trying to achieve. I have good results changing slide cutaway to alter low speed running. My dellorto manual says the shield is to keep fuel from pulling up the needle jet at low speed on 2 strokes when intake pulses backwards pulling fuel in 3 times before air gets to the combustion chamber.
 
Ref: 707 wing lift video.
The aircraft pilot, Tex Johnson, specifically states he did “...a Chandelle...”.
https://en.m.wikipedia.org/wiki/File:Chandelle.gif
The footage and the flight engineer’s photo purports to show inverted flight.
http://www.airlinereporter.com/2009/11/ ... x-johnson/

To the Norton owning aircrew out there, Is a ‘Chandelle’ also know as a ‘Barrel roll’ or is it just continued steep banking to reverse flight path?
Ta.
Barrel roll path: https://en.m.wikipedia.org/wiki/File:Ba ... e_view.jpg
 
The video taken from the ground shows it doing a full barrel roll.
Although its pretty small in the distance by then.
It keeps going straight ahead.

The video I've seen somewhere previously (on TV, as a doco) showed from inside the cabin, and the earth outside went fully turtle, then over and back level again.
As in, flying around the walls of a barrel, straight ahead.

707 prototype.
You don't often see the engines ABOVE the wings, unless its upside down...

http://www.airlinereporter.com/wp-conte ... 40x504.jpg

http://www.airlinereporter.com/2011/08/ ... rrel-roll/
Note the comments about showing how safe it was....

But we digress. Or is that the hijack continues - its all about Bernoulli...
 
Assuming newbi hobot-me knows too little to discuss this rationally with those who claim greater knowledge in this area please answer Ludwigs inquiry which remains up in the air.
what caused the 850 bog?
what new Amal feature solved it?
did the new feature solve it by richening or leaning in problem zone?
did it do this Most by air speed Benouli lowering pressure in spray tube or by piston decent pressure drop?

Highjacker hobot points out Magnus effect aircraft wings to ponder.
https://www.google.com/?gws_rd=ssl#q=sp ... 20aircraft
 
Post on Ludwigs updated version.
If you stay on topic, he can't castrate you, online !
I'm still pondering, some unanswered questions of of yet.
Its starting to sound like mutes restricted the zorst too much.... !

For those planning to fly upside down

Rowley's 400 and the Magic Tube , hijacked version .


make sure your fuel and oiling systems will work upside down !!
And your magnetic (?) boots are a good fit.
 
Young Author asked Merlin how he could recover desire to live after his gal gave it up to his best buddy.
Merlin said LEARN SOMETHING.

Besides the principles already mentioned there is also fluid bouncy-density to consider in *initiating* low pressure low flow states till threshold passed for other effects to take over. Still up in air on why a simple carb feature allowed 850 to be sold. Do not choke on this quote...

The advantage of Bernoulli’s principle over the stack effect is that it multiplies the effectiveness of wind ventilation. The advantage of stack ventilation over Bernoulli's principle is that it does not need wind: it works just as well on still, breezeless days when it may be most needed. In many cases, designing for one effectively designs for both, but some strategies can be employed to emphasize one or the other. For instance, a simple chimney optimizes for the stack effect, while wind scoops optimize for Bernoulli’s principle. - See more at: http://sustainabilityworkshop.autodesk. ... Q5VbH.dpuf
 
Talking about barrel rolling large aircraft. In one of his books, I think it's "Sigh for a Merlin", Alex Henshaw (Test Pilot) describes how as part of a display he would do a barrel roll in a Lancaster (WW2, 4 engine heavy bomber). He would judge the rate of roll by keeping a pair of gloves, previously place on top of the instrument panel, so that with negative "G" they would fly up to the top of the canopy, when he got the rate of roll just right the gloves would hover about 1/2 way up. This apparently places little or no abnormal stress on the airframe. The Lancaster being capable of carrying a 22,000 lb bomb load, had a good power/weight ratio when "empty", so Henshaw maintained.
cheers
wakeup
 
I'm not sure that this Amal problem the subject here isn't going to be (distantly) related to problems that early Spitfires etc had in WW2. ?

The early spits were carburetted, and in a dive the carburettors lost the plot (since gravity didn't hold the fuel down in the floatbowl), the carbs would flood out and the engine drown in fuel. The enemy exploited this = get into a jam and they dived, and the spits could not follow for long.
The solution was the famous Miss Shillers Orrifice.
https://en.wikipedia.org/wiki/Miss_Shilling%27s_orifice
Later Merlins got fuel injection, which dispensed with the problem entirely.

From what Bob Rowley seems to be saying, the mutes in the peashooters was causing problems with carburation,
and the cutaway spray tube solved it.
Although the timeframe remains to be seen, mutes were around well before the 850 models.

No, I am NOT saying that Commandos can fly inverted, before someone (almost certainly) throws that into the mix....
 
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