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Lift force acting on a fly line
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Re: Lift force acting on a fly line
Brilliant, Graeme!
Do you think that a similar experiment with same length sufficiently stretchy rubber bands inserted at regular intervals, so that we can see tension, would be feasible? A concern with this idea may be that the fly line may becomes too boingy and therefore not realistically representative?
Best regards,
Dirk
Do you think that a similar experiment with same length sufficiently stretchy rubber bands inserted at regular intervals, so that we can see tension, would be feasible? A concern with this idea may be that the fly line may becomes too boingy and therefore not realistically representative?
Best regards,
Dirk
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Re: Lift force acting on a fly line
That's great Graeme! Is this the line you are bringing Snakehead fishing?
Cheers, Paul
I believe that Lee has something like this.Do you think that a similar experiment with same length sufficiently stretchy rubber bands inserted at regular intervals, so that we can see tension, would be feasible
Cheers, Paul
Re: Lift force acting on a fly line
Excellent Graeme.
From a frustrated long time lurker.
Re: Lift force acting on a fly line
Welcome out IBM! And thanks, I'm glad you like it.
Thanks too Dirk. I think it might be possible to insert rubber bands, but I believe it might be too much for me to do it. If Lee has something like that already set up, I'd love to see how it goes.
Cheers,
Graeme
Thanks too Dirk. I think it might be possible to insert rubber bands, but I believe it might be too much for me to do it. If Lee has something like that already set up, I'd love to see how it goes.
Cheers,
Graeme
FFi CCI
Re: Lift force acting on a fly line
Graeme
Excellent video and I guess the trick was suggested by Vince. Here is another snapshot: Our eyes like to see what fits out thinking. Here is another picture from the video. The yellow lines show the tangential direction of “rotation speed” and the blue ones the horizontal direction of the front loop speed (best guess in both cases). The green lines show the direction of the theoretical resulting air flow which cuts the angle between blue and yellow lines in two equal parts. If you look at the two visible tails in the inclined section, the theoretical approach does not look so wrong sometimes.
Merlin
Excellent video and I guess the trick was suggested by Vince. Here is another snapshot: Our eyes like to see what fits out thinking. Here is another picture from the video. The yellow lines show the tangential direction of “rotation speed” and the blue ones the horizontal direction of the front loop speed (best guess in both cases). The green lines show the direction of the theoretical resulting air flow which cuts the angle between blue and yellow lines in two equal parts. If you look at the two visible tails in the inclined section, the theoretical approach does not look so wrong sometimes.
Merlin
Fly rods are like women, they won't play if they're maltreated
Charles Ritz, A Flyfisher's Life
Charles Ritz, A Flyfisher's Life
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Re: Lift force acting on a fly line
As I watch them go around the point of the loop, Merlin, they all are pointing straight up. At the bottom of the loop they often align at a slight angle backwards. I found this very interesting and I think it means that there is some forward movement of the line in the rod leg. From the tracker videos I believe that we have seen this.
Cheers, Paul
Cheers, Paul
Re: Lift force acting on a fly line
I've got a large selection of videos to choose from Merlin. They all show the same thing I've described above. This is a VERY repeatable experiment. Please try it yourself.Merlin wrote: ↑Sun Jul 14, 2019 9:24 am Our eyes like to see what fits out thinking. Here is another picture from the video. The yellow lines show the tangential direction of “rotation speed” and the blue ones the horizontal direction of the front loop speed (best guess in both cases). The green lines show the direction of the theoretical resulting air flow which cuts the angle between blue and yellow lines in two equal parts. If you look at the two visible tails in the inclined section, the theoretical approach does not look so wrong sometimes.
Merlin
The tracking data from earlier casts shows there is no "rotation speed" of any point in the rod leg unless it's a snap cast. The points move forward in the fly leg until they hit the loop, at which point they go straight down in the rod leg (in a tethered cast). Your tangents are things you want to see but aren't really there. If you'd like me to track these tell-tails to show you that, I can do so. Just say the word.
Yes Paul, there is a little forward movement of the line as the cast progresses, so the tell tails lay back somewhat, and even point down as the rod tip bounce travels along the rod leg towards the loop.
(And no, this was my idea. I came up with it after ongoing discussions with Vince, but it was part of a bigger experiment in which the fly line was paired to a 3 metre length of wool. This it the aftermath after the wool was mostly removed. Did you know that dramatically increasing skin and form drag on a Rio Permit line doesn't add any lift to the cast either?)
Cheers,
Graeme
FFi CCI
Re: Lift force acting on a fly line
These are the paths of the bits of wool. What was the theoretical path supposed to look like? Where is a tangent applicable?
FFi CCI
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Re: Lift force acting on a fly line
That’s a truly excellent experiment, Graeme. Thank you!