'I don't believe planes can fly' blog discussion

2sides2everystory

taxedtodeathbylabour wrote: »

Well lets see, we could start by employing member of parliment support officers. They could do the job for a third of the price. They would not have any real powers to make decisions, just to be there in HI VIS suits so that are visible.
Then we could reduce the number of MP's by 20%, roughly by 130 or so. MP's would have to have a licence to work an MP. This would be issued by a governing body and would have to be paid each year by the MP's themselves, say £1000 per year to practice.
When MP's stand down especially after lost election we should remove there thank you and goodbye payment. Expenses will only be paid with a receipt and must be proportionate and justifiable, e.g. first class plane ticket is not proportionate when using tax payers money.
As an MP you must work until you 95; and pay 46% of your wage towards your statue in the house of commons if your the PM. :rotfl:

Sadly that one won't fly, TTDBL

eeeeeee

you cant beat a descent old spot too get you too tenerife for your winter hols :rotfl::rotfl::rotfl:

John_Pierpoint

Reaper wrote: »

Lol. Most people think the plane stays in the air because of the airflow hitting the underside of the wing. If this were all it had it would indeed fail to fly and you would be right to be worried.

In reality that accounts for only about 20% of the lift. The remaining 80% comes from low pressure ABOVE the wing sucking it upwards.

It's a bit hard to explain why but I will try. The curved surface above the wing means the airflow has to travel faster over the top than it does underneath. That leads to a drop in air pressure which sucks it up.

You can try this for yourself. Get 2 sheets of paper and hold them close together then blow in between them. You might think they would separate more but they don't - they get closer together. The fast moving air between them is at a lower pressure than the still air outside so it pulls them together.

That is how a wing holds a heavy plane up, as long as it keeps moving and keeps that airflow passing over the wing.

It is also the reason why I find light weight shower curtains an abomination.
As the water droplets drop through the air, they make a breeze, the moving air is at a lower pressure. So the nasty wet clammy shower curtains are pulled against your legs.

It was the Elizabethan "Martins" who thought the answer to a smoking fire place was to make the fire place and chimney even bigger to catch the smoke; when in reality (as long as it was kept swept) a smaller chimney would make the chimney speed up the column of smoke and thus "suck" better.

Don't school open days still include an exhibit from the science department any more; Putting an airflow through a venturi (a restriction shaped a bit like a power station's cooling tower) means a manometer measuring the pressure in the wide part of the pipe and the restricted part of the pipe, demonstrates that the fast moving flow in the restricted part is at a lower pressure.
I find this counter-intuitive, one would have thought the bottleneck would be bursting to push out the walls of the tube, not sucking to pull them in.

Half way down the page offered by this link, there is an illustration of such a venturi demonstration.

http://www.flowmeterdirectory.com/flowmeasurement.html

Reaper

John_Pierpoint wrote: »

It is also the reason why I find light weight shower curtains an abomination.
As the water droplets drop through the air, they make a breeze, the moving air is at a lower pressure. So the nasty wet clammy shower curtains are pulled against your legs.

I suspect this has another simpler explanation. The air inside the shower cubicle is heated by the hot water passing through it. The heated air attempts to rise and cold air from outside attempts to move in below it from outside. If the curtain is light this pressure is enough to make it move inwards.

John_Pierpoint

I agree it is hotter, but that would make it expand. I am absolutely certain the air is moving downwards not upwards - check the "steam".

2sides2everystory

Do you think it's "circulation" again John ? ... or at least as Reaper implies, some kind of active convection, as in some highly localised thunderstorm type weather system perhaps :rotfl:

Clammy legs or not, I wouldn't recommend raising the undercarriage in this one ...

tabbytabby

Lol I think its the big turbines attached the wings that helps the plane move forward and 'fly'. Unlike the birds and the bees that flapped their wings to go into the sunset.