Ball flight laws and misinformation

[iacas]

Oh, this again. Goody. :P I've merged this into what seems like an appropriate existing thread.

Originally Posted by Hacker James

I had been reading several posts about how even some of the pro golfers "feel" one thing and do quite another. The one article that caught my interest was Sir Nick Faldo's explanation of how he hit around the tree.

Nick's body learned to over-ride what his mind told him he was trying to do. If he truly had the clubface pointed at the tree at impact, he'd hit the tree.

Originally Posted by Hacker James

I have always been able to hit a fade fairly well without even thinking about it. I wanted to try and follow the "new" rules to the letter. I was set up about 20 yards away. I set up with open stance, open club face, swinging along the stance line. I happened to have a seven iron. Now unless I had interpreted the rules incorrectly, the ball should have curved back towards "0", but instead it looked like a dead pull.

First, I don't like the words "open" for everything here. How open? If I set up 20 yards left but point the face 50 yards right, the ball will not finish at the target. It'll start almost 50 yards right and slice from there. It also won't go very far. :)

To fade a ball around a tree: point the clubface just left of the edge of the tree, and swing farther to the left than that. This must be done AT IMPACT. What you do in your setup can help but in no way actually determines what you'll do at impact. I could take a grip, and twist the club so it's pointing at my left ankle at setup - doesn't mean I'm going to return it pointing there.

Your clubface and path matched enough that you hit a ball straight left. You swung left with a face pointing in roughly the same direction.

You didn't interpret the "rules" incorrectly - you simply didn't pull off what you were trying to pull off.

Originally Posted by Hacker James

This leads me to believe that the distance I was hitting from was not along enough with the seven iron to notice the curve back.

That doesn't make sense. A lower lofted club will curve more. It's difficult to curve a pitching wedge. Watch this (if you're bored).

Originally Posted by Hacker James

I sincerely believe the new laws are correct in all aspects

There's no need to "believe." They are correct.

Originally Posted by Hacker James

I know this is an old worn out thread topic, but I just wanted to point out how our "feel" can "fool" us.  Unless, of course, I missed something or my understanding is flawed.

Feel ain't real. Probably the three words I've typed the most in sequence that aren't the common phrases like "I think that" or whatever.

[Mwferguson]

What's wrong with the video exactly? I guess I don't understand. As long as the face is open to the path the ball fades and closed to the path it draws?

That is how I understand it. Looks like on the video looks on the video looks body is left of the target making his target line to be just left side of the green. After impact the club should be exiting left anyway.

What am I missing here?

[iacas]

What's wrong with the video exactly?

I think if you read through the thread, you'll see what people found to be misleading about the video.

Yes, if the clubface is closed to the path, the ball draws. But where the ball starts (hint: it's not along the swing path) is the main issue.

[mdl]

To me the main point in this apparently endless debate is not really the argument about the physics and percentages, but the implications for fixing problems.  I'm working on hitting a push draw after years of not really being able to hit any (good) shot except a straight shot or baby straight-fade.  One of my misses with this new stroke is a shot that feels like the club head was on a good path, with a divot to back that up a bit, but the ball starts just a touch right of the target and then draws too strongly well left of the target.  I'm thinking here of something like a 5i approach on a par 3, where it's not an ugly snap hook, just starts a tad right of the middle pin and then draws too much into the left side bunker of a pretty wide green.

With the new ball flight laws in mind I know that I hit the ball with a reasonable in to out path but my club face was pointing right at the target at impact instead of being slightly open to the target.  It started just a touch right due to the 15%.  So I fix that by trying to figure out how not to close the club face quite so much by impact while maintaining the same swing path.

With the old ball flight laws in mind, I think I hit the ball with a closed club face and a straight swing path, so I am correctly going to try to open the club face a bit at impact but I'm also going to try to hit even more in to out.  This will most likely result in a big hook that starts right of the target but hooks way left.

[Lihu]

Check this out, they've started to model the golf ball dimples and their effects with airflow.

[colin007]

That's nuts...

[Lihu]

That's nuts...

Yeah, totally.

I Wonder how or if they verified the model? It would take really tiny sensors to measure it without upsetting the flow.

[David in FL]

Very cool. Just serves to remind me that there are a LOT of people a LOT smarter than I'll ever be! :8)

[RandallT]

[QUOTE name="colin007" url="/t/56453/ball-flight-laws-and-misinformation/72#post_1069376"] That's nuts...[/QUOTE] Yeah, totally. I Wonder how or if they verified the model? It would take really tiny sensors to measure it without upsetting the flow.

[quote name="David in FL" url="/t/56453/ball-flight-laws-and-misinformation/60#post_1069388"]Very cool. Just serves to remind me that there are a LOT of people a LOT smarter than I'll ever be! :8)[/quote] I know they're smart and all, but I hope they are modeling a spinning golf ball to add complexity. It just looks to me like they think the ball is stationary in flight like an airplane wing :)

[iacas]

I know they're smart and all, but I hope they are modeling a spinning golf ball to add complexity. It just looks to me like they think the ball is stationary in flight like an airplane wing :)

Yeah. Pretty sure you're right.

[David in FL]

I know they're smart and all, but I hope they are modeling a spinning golf ball to add complexity. It just looks to me like they think the ball is stationary in flight like an airplane wing :)

I'm guessing that they realize that a golfball spins......

[iacas]

I'm guessing that they realize that a golfball spins......

It's not demonstrated in the video at all.

[MS256]

Hmmm. I'm not anti-engineering but I've had to explain to them why their plans wouldn't work in real life on a shop floor an awfully lot of times. Not to mention showing them how to change their flat tire. ;-) Just joking around a little. I have known a few that had both common sense and mathematical sense. Those are worth their weight in gold.

[David in FL]

It's not demonstrated in the video at all.

All the video seems to do is model how air flows across an individual dimple. Just as you would model the airflow across the wing of a plane, or the body of a car by showing the plane/car stationary with the air moving across it, even though it's the actual movement of the plane/car through the air mass that's causing the actual relative airflow. I'm gonna give the engineers a little credit here and assume that they understand that the ball spins and that the manner that the air flows from dimple to dimple is important.

[saevel25]

I'm gonna give the engineers a little credit here and assume that they understand that the ball spins and that the manner that the air flows from dimple to dimple is important.

[boogielicious]

Computational Fluid Dynamics has been around for a long time.  We've used it to model mixing of fluids.  I am sure that the major ball companies have also been using it for a while.  This model presented in the video may have added variables that were not possible before due to computer power required.  Example: adding spin would add a position variable.  The reason it requires a super computer is because the program is iterative.  It does the calculation of each step.  If you make the steps really small, then there are trillions of calculations.

They've added graphics, which increases the complexity by orders of magnitude as well.  Looks cool though, doesn't it?

[iacas]

All the video seems to do is model how air flows across an individual dimple. Just as you would model the airflow across the wing of a plane, or the body of a car by showing the plane/car stationary with the air moving across it, even though it's the actual movement of the plane/car through the air mass that's causing the actual relative airflow. I'm gonna give the engineers a little credit here and assume that they understand that the ball spins and that the manner that the air flows from dimple to dimple is important.

I'm not. A dimple moving toward or away from the direction of flight changes the airflow. Even something as simple as the angle of the dimple relative to the airflow severely changes things.

[David in FL]

I'm not. A dimple moving toward or away from the direction of flight changes the airflow.

Even something as simple as the angle of the dimple relative to the airflow severely changes things.

The ball is round, so every dimple is presented to the air mass differently whether the ball is spinning or not, so obviously the direction of the relative airflow across each dimple has to be considered in relation to the whole.  Something clearly outside the scope of this short, informational video.

I'm not saying that spin doesn't affect the dynamics of flight, of course it does.  Just that because the model representation shows the air moving, rather than the ball, doesn't mean that the engineers don't understand that the ball spins.  I'm surprised that anyone would think that somehow they don't......

Computational Fluid Dynamics has been around for a long time.  We've used it to model mixing of fluids.  I am sure that the major ball companies have also been using it for a while.  This model presented in the video may have added variables that were not possible before due to computer power required.  Example: adding spin would add a position variable.  The reason it requires a super computer is because the program is iterative.  It does the calculation of each step.  If you make the steps really small, then there are trillions of calculations.

They've added graphics, which increases the complexity by orders of magnitude as well.  Looks cool though, doesn't it?

Yes it does!