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## Search found 1372 matches

Mon Aug 24, 2020 6:45 pm
Forum: Flycasting Physics
Topic: The Triple or Check Haul
Replies: 72
Views: 5864

### Re: The Triple or Check Haul

Merlin, Here are the comparative speed curves that include the y velocity variations in that video to arrive at speed variations for the different legs and loop. The thick red line is the expected loop speed based on the sqrt(sum of squares) of the .5(v1 +v2) values in the x and y directions. That e...
Fri Aug 21, 2020 12:47 pm
Forum: Flycasting Physics
Topic: Covered topics /how it works
Replies: 130
Views: 8847

### Re: Covered topics /how it works

So now, what lifts Anna Hedman's line into the air from where it was sat on the ground?
James,
The same thing. The dp/dt momentum change of line ahead of it.
Gordy
Fri Aug 21, 2020 12:31 pm
Forum: Flycasting Physics
Topic: Covered topics /how it works
Replies: 130
Views: 8847

### Re: Covered topics /how it works

Now let me ask you a very simple question (which no doubt you'll avoid) - what's the driver for the string lifting in this example? Is it pixies or the fact I've thrown the fucking nut James, I would say it comes from the dp/dt momentum change of the nut. The nut would go faster if it was not pulli...
Thu Aug 20, 2020 10:37 pm
Forum: Flycasting Physics
Topic: Covered topics /how it works
Replies: 130
Views: 8847

### Re: Covered topics /how it works

I'd say the overriding reason behind loop morph is fly-leg momentum pulling the rod-leg taut and I thought what I meant was so obvious that I didn't need to explain it further. James, You know that momentum is not a force, but many readers of this forum do. Same thing goes for inertia. Thus that st...
Thu Aug 20, 2020 8:04 pm
Forum: Flycasting Physics
Topic: The Triple or Check Haul
Replies: 72
Views: 5864

### Re: The Triple or Check Haul

I didn't ask about density, I asked about viscosity, don't you know the difference? James, There is no viscosity term in the drag equations that I use. The kinematic viscosity for air does impact the Reynolds number, which in turn can impact the drag coefficient, but generally the Reynolds number i...
Thu Aug 20, 2020 4:56 pm
Forum: Flycasting Physics
Topic: The Triple or Check Haul
Replies: 72
Views: 5864

### Re: The Triple or Check Haul

In your calculations (Gordy, Daniel), do you account for the real viscosity of air? James, I use the value that Noel Perkins gave in his drag-related papers. \rho_{air}=1.29 Kg/m^3 . I see the ISA value is: According to the International Standard Atmosphere (ISA) values—15° C at sea level—the densi...
Thu Aug 20, 2020 4:37 pm
Forum: Flycasting Physics
Topic: The Triple or Check Haul
Replies: 72
Views: 5864

### Re: The Triple or Check Haul

By the way the angular momentum effectively depends on the [square] of the loop “radius” (it is pi*rho line*radius squared*tangential velocity), and this might be involved in loop morphing as well Merlin, I am glad that at least two of us have reached a consensus that the angular momentum of a dist...
Thu Aug 20, 2020 4:14 pm
Forum: Flycasting Physics
Topic: Covered topics /how it works
Replies: 130
Views: 8847

### Re: Covered topics /how it works

I'd say the overriding reason behind loop morph is fly-leg momentum pulling the rod-leg taut
James,
Are you implying that momentum is some type of force that can pull on the rod leg? I thought it took a change in momentum to produce a force.
Gordy
Thu Aug 20, 2020 2:07 pm
Forum: Flycasting Physics
Topic: The Triple or Check Haul
Replies: 72
Views: 5864

### Re: The Triple or Check Haul

I realized that the loop would certainly never go backwards even with a drastic PB; and That would certainly be something to check out as I don't see why the loop would start to act as a stationary peg when its propagation velocity goes to zero. Merlin, It is not much but using Tracker to mark the ...
Thu Aug 20, 2020 12:40 pm
Forum: Flycasting Physics
Topic: The Triple or Check Haul
Replies: 72
Views: 5864

### Re: The Triple or Check Haul

I realized that the loop would certainly never go backwards even with a drastic PB; Merlin, That would certainly be something to check out as I don't see why the loop would start to act as a stationary peg when its propagation velocity goes to zero. Since we only have a one dimensional model at thi...