Upward Force from Form Drag

[gordonjudd]

If you've read anything of what I've written you'll know I talking about increasing the launch speed. It's almost like your being deliberately obtuse to avoid discussing the main issues.

James,
I am sorry that my "corrections" have seemed obtuse to you, but bare in mind I can only respond to what you say, not what you mean.

change:

but surely it's obvious that the greater the fly-leg momentum then the greater the rate of change?

to "but surely it's obvious that the greater the fly-leg velocity then the greater the rate of change?" I would have agreed with you, because the change in the momentum depends on the Vfly.^2/4.

As to the main issue I hope you agree that its is the force the results from the change in the momentum as the loop propagates that is of interest, not the magnitude of the momentum itself. As you know the magnitude of the momentum does not have anything to do with forces, but the change in the momentum does.

Gordy

[Stoatstail50]

https://vimeo.com/17266598

I can remember this from years ago...a new "loop" forms.

Loops are just artifacts, an inevitable product of the relationship between the fly leg moving forwards and the caster hanging on to one end of the rod leg. I used to think they were interesting...but they're not really. It's a pushmi-pullyu. And I agree with Graeme, no force, no momentum change.

[James9118]

I am sorry that my "corrections" have seemed obtuse to you, but bare in mind I can only respond to what you say, not what you mean.

Change to "but surely it's obvious that the greater the fly-leg velocity then the greater the rate of change?" I would have agreed with you, because the change in the momentum depends on the Vfly.^2/4.

Gordy

Gordy,

In my first post I noted:

just a bit more extreme in the arc used and linespeed generated (thus giving the fly-leg more momentum)

In a later one I stated:

The 170 (bouncing bomb) cast is no different from any other cast, just a bit more extreme in the speed produced in the fly-leg

So you're not correcting anything, you're being deliberately obtuse trying to pick pedantic holes in what people are saying rather than tackle the gigantic hole in the 'drag induced lift' hyporthesis.

So answer the main question - why can't I get a side cast to veer to the right?

James

[Lasse Karlsson]

https://vimeo.com/17266598

I can remember this from years ago...a new "loop" forms.

Loops are just artifacts, an inevitable product of the relationship between the fly leg moving forwards and the caster hanging on to one end of the rod leg. I used to think they were interesting...but they're not really. It's a pushmi-pullyu. And I agree with Graeme, no force, no momentum change.

Miss a thumbs up emoji here!

Cheers
Lasse

[Merlin]

No force? Even aerodynamics?
I think you are simplifying the issue too much. Casts would be very different without those forces.

Merlin

[Stoatstail50]

No force? Even aerodynamics?
I think you are simplifying the issue too much. Casts would be very different without those forces.

Merlin

Should read “if there is no force, there will be no momentum change”

As far as I know there are three forces in play, gravity, friction or drag and the caster holding up the rod/line at one end...are there any more ?

[Merlin]

Thanks for the clarification.
Agreeing with Mr Newton is mandatory

Merlin

[TrevH]

“Sir” (Isaac ...)

[VGB]

Vince,
So how would you compute the magnitude of the green vector in your diagram? Based on the tilt angle and the Fd magnitude of the drag force due just to form drag on the inclined section of line?
Gordy

Gordy

Apologies for the delay, password issues. I would use the lift equation to calculate lift (green axis) from the resultant aerodynamic forces due to the interaction of the free stream flow with the inclined section of line

https://wright.nasa.gov/airplane/lifteq.html

[VGB]

“Sir” (Isaac ...)

Not Olivia