ChatterBank3 mins ago
Flag Wrapping.....
26 Answers
Ok can someone explain the science here. A club I go to has a flag pole and when a member dies we put the flag at half mast. Our flag pole is on the side of the building high up at an angle of approx 45 degrees. Now, inevitably, when a wind gets up it gets wrapped around the pole. What I don't get is, why does it never unwrap itself, the wind blows in all directions but the flag will only wrap in the same direction as its first wrap, getting more and more wrapped around the pole. I have never seen it unwrap, ever. I'd have though that if the wind changed direction it would unwrapaAny ideas why not? thanks
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For more on marking an answer as the "Best Answer", please visit our FAQ.Also having a stab at it! Is it possible that the wind rubbing against the cloth induces a charge of static electricity in the cloth which causes it to stick to itself and therefore becomes more difficult to unwrap due to this adhesion????
What material is the flag made from???
I'm probably talking rubbish but you never know!
What material is the flag made from???
I'm probably talking rubbish but you never know!
As the wrap can be in both directions, it has to be related to the wind direction on that particular day.
Chuck; The pole is at 45 degrees, so unless some device is also fitted, the uppermost ring would descend down the pole. Also flagpoles usually have a finial on the end which would hamper the sliding on of the rings.
Chuck; The pole is at 45 degrees, so unless some device is also fitted, the uppermost ring would descend down the pole. Also flagpoles usually have a finial on the end which would hamper the sliding on of the rings.
"Chuck; The pole is at 45 degrees, so unless some device is also fitted, the uppermost ring would descend down the pole."
The kits for it come with a circular clamp that goes around the pole to stop just that happening. also the finial can normally be unscrewed on most poles, but if not the rings can probably be fitted by taking the pole out the mount and putting them on from the bottom.
http:// www.usf lags.co ...s/th umbs/00 01699.j peg
The kits for it come with a circular clamp that goes around the pole to stop just that happening. also the finial can normally be unscrewed on most poles, but if not the rings can probably be fitted by taking the pole out the mount and putting them on from the bottom.
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I''m not sure whether this explanation is correct but here goes:
Air flowing above a certain velocity past a pole at right angles, generates turbulence eddies which break away from the pole sides alternately. This is what makes taut strings vibrate in the wind. When the flag has been wrapped once the aerodynamics of the pole/flag combination are asymmetrical so the eddies break away on one side only, this happens to be the side which wraps the flag again the same way. The wind direction would not make any difference.
Air flowing above a certain velocity past a pole at right angles, generates turbulence eddies which break away from the pole sides alternately. This is what makes taut strings vibrate in the wind. When the flag has been wrapped once the aerodynamics of the pole/flag combination are asymmetrical so the eddies break away on one side only, this happens to be the side which wraps the flag again the same way. The wind direction would not make any difference.
The region with the lowest air pressure will be on the lee side where the flag is closest to the pole. The pole edge of the flag will try to move into this region. Once the process has started, it will continue. Even when the low pressure region is facing the wind, it will maintain the lowest air pressure, and the nearest part of the flag will keep trying to move into it. If the wind is strong enough the drag on the rest of the flag will keep it flying straight. But if the wind is gusty, each time the wind drops a bit, and drag is reduced enough, the flag will again try to move into that lowest pressure region, and end up being wrapped round the pole.
Working on an a priori basis that jomifl and/or Heathfield are correct, (I can't contradict either of them!) you are still stuck with the problem, and only chuck has given a satisfactory way out of it. I would further suggest that you re-position the flagpole vertically, which is after all the proper, correct historical orientation for flags, - 45 degree poles are namby-pamby.
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