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billvon 2,384
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>A canopy traveling faster doesn't create more turbulence.
Correct. But a canopy traveling faster SEES more turbulence.
Turbulence isn't static; it's not just sitting there, waiting. All turbulence is is moving air. Wind is air all moving in the same direction; turbulence is wind that's moving in different directions depending on where you are. If you are standing still with respect to the average wind you feel very little turbulence. If you're moving you feel it as you move from one area of wind to another. The faster you go, the faster the winds change direction and the more turbulence you feel.
When airplanes encounter severe turbulence they slow down to avoid overstressing their flight surfaces. The slower the aircraft goes, the less change it sees per unit of time, and the less force that wind can apply to the aircraft. However, slowing down too much (say to near stall) also isn't a good idea - if you are 10 knots above stall, then flying into a region with a 12 knot gust from behind you will stall the airplane.
Canopies can't change their airspeed without distorting their airfoil shapes, and most modern canopies are most stable either at full flight or with very slight brakes applies. Thus it's generally better to be flying at full flight (or close to it.) But flying faster to "keep your wing pressurized" and/or "cut through the turbulence faster" doesn't work.
Correct. But a canopy traveling faster SEES more turbulence.
Turbulence isn't static; it's not just sitting there, waiting. All turbulence is is moving air. Wind is air all moving in the same direction; turbulence is wind that's moving in different directions depending on where you are. If you are standing still with respect to the average wind you feel very little turbulence. If you're moving you feel it as you move from one area of wind to another. The faster you go, the faster the winds change direction and the more turbulence you feel.
When airplanes encounter severe turbulence they slow down to avoid overstressing their flight surfaces. The slower the aircraft goes, the less change it sees per unit of time, and the less force that wind can apply to the aircraft. However, slowing down too much (say to near stall) also isn't a good idea - if you are 10 knots above stall, then flying into a region with a 12 knot gust from behind you will stall the airplane.
Canopies can't change their airspeed without distorting their airfoil shapes, and most modern canopies are most stable either at full flight or with very slight brakes applies. Thus it's generally better to be flying at full flight (or close to it.) But flying faster to "keep your wing pressurized" and/or "cut through the turbulence faster" doesn't work.
pchapman 261
Still, a given size of gust will cause a lower change in angle of attack for a wing at higher speed. In that sense one can 'cut through' turbulence -- less likely for a down gust to unload the front of the wing and collapse it.
On the other hand, more speed gives less time for the canopy to adapt to a new angle of attack and thus can 'get hit' by turbulence if flying faster instead of having time to react and adapt to the new conditions if flying slower. Which could be good or bad depending on the situation. (Eg if you get hit by some idealized upwards gust before hitting a following downwards gust -- the down gust isn't as extreme a change if the wing hasn't already reacted to the up gust. In that particular situation, more speed is again better. But if it is a down gust followed by more down gust, the wing moving with the conditions can be better.)
I think it will depend on the exact natures and scale of the turbulence, which factor wins out. Still, I think extra speed tends to win out as better. (At least as long as one doesn't actually have a collapse -- then slower can be better in many circumstances.)
On the other hand, more speed gives less time for the canopy to adapt to a new angle of attack and thus can 'get hit' by turbulence if flying faster instead of having time to react and adapt to the new conditions if flying slower. Which could be good or bad depending on the situation. (Eg if you get hit by some idealized upwards gust before hitting a following downwards gust -- the down gust isn't as extreme a change if the wing hasn't already reacted to the up gust. In that particular situation, more speed is again better. But if it is a down gust followed by more down gust, the wing moving with the conditions can be better.)
I think it will depend on the exact natures and scale of the turbulence, which factor wins out. Still, I think extra speed tends to win out as better. (At least as long as one doesn't actually have a collapse -- then slower can be better in many circumstances.)
Pulse 0
Quote>A canopy traveling faster doesn't create more turbulence.
Correct. But a canopy traveling faster SEES more turbulence.
You're right. We're on the same page. I just wanted to be clear as to what you were saying.
"Any language where the unassuming word fly signifies an annoying insect, a means of travel, and a critical part of a gentleman's apparel is clearly asking to be mangled."
Pulse 0
[replyYou forgot to mention the planform which will greatly effect the result of turbulence. Its funny that you mention that Jonathan because when I read this topic I remembered how my Jonathan was particularly suceptible to collapse ![[:/]](/uploads/emoticons/dry.png "[:/]"){kind=small}
Given that ellipticals are a bit more 'unstable', I assume you mean the results of turbulence can be more dramatic if you're not on it right away. I don't know how much planeform lends a canopy to be more prone to collapse or not.
I didn't feel my Jonathan was any more prone to collapse. I only had the one instance and that was the result of a few factors. Mostly my fault.
Just a point. There is a difference between collapsing and just getting blown around by turbulence. Most 'collapses' I've heard people talk about are usually the latter when I've seen them. That's not to say it matters much to the person under canopy, Since both experiences can be iffy. But all out collapses are pretty rare all things considered.
"Any language where the unassuming word fly signifies an annoying insect, a means of travel, and a critical part of a gentleman's apparel is clearly asking to be mangled."
billvon 2,384
>Still, a given size of gust will cause a lower change in angle of attack for a wing at
>higher speed.
But a greater force. Which is why aircraft generally slow down when encountering turbulence.
Aircraft, of course, have an advantage that we don't - their wings are rigid, and even the weakest rigid wing can withstand some negative G's. Which is why it's pretty important for us to avoid negative loading.
>higher speed.
But a greater force. Which is why aircraft generally slow down when encountering turbulence.
Aircraft, of course, have an advantage that we don't - their wings are rigid, and even the weakest rigid wing can withstand some negative G's. Which is why it's pretty important for us to avoid negative loading.
You forgot to mention the planform which will greatly effect the result of turbulence. Its funny that you mention that Jonathan because when I read this topic I remembered how my Jonathan was particularly suceptible to collapse
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