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Re: The Square-Cube law........

By: Cactus Flower in ALEA | Recommend this post (0)
Tue, 24 Jun 14 2:10 PM | 43 view(s)
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Msg. 15736 of 54959
(This msg. is a reply to 15734 by faul)

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so are you actually going to admit your old formula was bollox?

which means until i pointed it out, your theory was based on bad maths.

or is the theory immune to discoveries of this type? the numbers don't matter. the theory remains the same whatever numbers are used.

0.53/0.86 does not equal less than 40%. let's start with that and work back from there to your theory.

if your theory was that 62% was less than 40%, is there something wrong with your theory?

if the theory is not sensitive to an error of >50% (ie (100*62/39)-100), perhaps the theory is what matters and not the numbers.

and perhaps your maths is the root cause of your suspicions.

so you employ an irrelevant operating velocity used for minimising maintenance costs to imply an engine's thrust capability and an erroneous fraction of that figure to lower the velocity in mph. and now you are trying to change planes to a 777 and a 747?

i'm not being unkind. but accurate maths actually matters to your theory. it isn't a minor problem when you make errors when you purport to explain your theory. until the numbers demonstrate the issue, you have a theory but no support for it.

just let me know when you are making an argument that addresses the issue of break-up velocities for the relevant plane and the actual velocity of the aircraft on its approach to the twin towers upon which your conspiracy theory depends.

only number i have heard for the break up speed is mach 0.86 at any altitude. this also conforms with the way sound shock waves seem to work. but if there's a lower break up velocity for this plane at low altitude, i'll be happy to work with that. i've even suggested there may be a speed limit due to engine heat and friction at low altitudes which is independent of a higher frame limit.

even so, operating velocities won't suffice as the basis of any calculation. maintenance velocities have no obvious relationship with an engine's capabilities. one defines a wear and tear measure. the other the aircraft's ability to increase velocity. and break up speed represents something quite different again. it's the velocity at which the atmosphere's resistance begins to disintegrate the aircraft, which isn't a measure of thrust at all, although an aircraft has to be able to reach a velocity in order to disintegrate at it.


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The above is a reply to the following message:
Re: The Square-Cube law........
By: faul
in ALEA
Tue, 24 Jun 14 12:33 PM
Msg. 15734 of 54959

OK lets use the FAA data supplied in those PDF's..

Boeing 777....0.50M at sea level,0.86M at 35,000 ft
Boeing 747....0.55M at sea level,0.92M at 35,000 ft

Boeing 777...0.50 of 0.86=72%
Boeing 747...0.55 of 0.92=67%

Boeing 777...0.50 x 761mph=380.50mph Max Mach MMO
Boeing 747...0.55 x 761mph=418.55mph Max Mach MMO

Boeing 777...Max calibrated airspeed 380mph at SL
Boeing 747...Max calibrated airspeed 419mph at SL

Do you agree with the maths or is it curious?


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