Why riding the wind is longer?

[DeanB]

I've been trying to figure out the physics behind cross wind shots.  I can understand and caculate the effect of curving the ball against a cross wind which makes the ball carry shorter and stop sooner.

Does anybody have an explanation on how curving the ball WITH the wind can produce a longer shot?

E.g. if one hit a fade into a left to right wind, the ball will land and travel sideways to the right.  How does that make the ball rest closer to the green?

Thanks.

[Stretch]

Isn't any curved shot traveling both with and against a cross wind for a certain portion of its flight? Say a right-handed fade with the wind 90 degrees from the left: From impact until the apex of its curvature, the ball is traveling upwind (right to left). From the apex until it lands, it is traveling downwind (left to right). Right-handed draw, vice versa. Obviously the wind strength is going to influence the total amount of curve for any given spin axis and my guess is that's a factor in any distance variation -- your fade in this case is going to travel downwind for a longer portion of its flight time. Another possibility is that the tilt of the spin axis relative to the wind direction will add or subtract some aerodynamic lift. I don't know, just thinking alound.

[DeanB]

I can see that curving the ball with the direction of the cross wind might get the ball farther away from the tee box (in the next fairway maybe).  As an extreme example, one can hit a shot 90 degrees to the right in a left to right wind and get the maximum distance.  It'd be like hitting a ball down wind.

Still not sure why would it be closer to the green.

When the pros talking about curving the ball with the wind, do they really fade the ball on a left to right wind?  Or do they hit a straight shot to the left of the target and let the wind fade it?

[soxagolf]

Think of air as you would water. Gravity and friction from the air (I think) are the only two forces acting against your golf ball; if the air is moving with your ball instead of against it, the air the ball moves through causes less friction. Water works the same way, if you threw a golf ball into a slide with water flowing 1) toward the ball, 2) neutral, 3) against the ball, you'd fairly obviously get differences in distance.

From what I remember in my physics class, most of fluid dynamics (air and water) just has to do with friction and pressure. Friction would be the direction of the wind (or how the molecules are moving relative to the object), pressure would be the density of the air (how close the molecules are to each other).

[saevel25]

Ok, the only way the ball will go farther is if the wind has some vector thats going with the ball.

So if you draw a line straight down the fairway, and then draw a perpendicular line. Some of the wind must go from the tee box to the green. Now lets say you have right to left wind, with a bit going towards the hole. You hit a draw, it will go less than if you hit a fade. The reason is that the ball with a draw has a vector that goes from right to left and towards the hole. So, that right to left vector is decreased by the left to right wind.

So if

Ball speed = Vx + Vz + Vy

Wind speed = Wx + Wz + Wy

Lets say x is going from tee to green, z is going from right to left, and y is going from ground to sky. Now, a draw on the ball would be

Ball speed = Vx + Vz (i took out the vertical component for simplicity)

With that notation the

Wind speed = Wx - Wz, because the wind speed is from left to right

So the overall ball speed is (Vx + Wx) + (Vz - Wz)

So, if the wind speed is primarily left to right, then Wx would be very small, and the draw would hold up againts that wind and the ball would loose some speed. If you hit a fade, then you will have (Vx + Wx) + (-Vx - Wz), don't worry about the negative, the overall ball speed down the fairawy, neglecting the vertical is just

total ball speed = square root of (Vx+Wx)^2 + (-Vz-Wx)^2

So the negative is turned into a positive and combined with the x vector. So its an overall gain of ball speed in the air for a fade with a left to right wind, and a decrease in speed for a ball with draw spin.

Now, spin does some freaky stuff, This is just a simplistic view of why the ball would go farther if you ride the wind. Though i think the overall best deal is try to hit a push with the wind going from left to right, because you gain most Vx distance, and add a bit of Wx to the ball speed. But thats my opinion.

[newtogolf]

The physics equations cover a smooth surface sphere or ball, but I'm not sure they apply the same way when dimples are added to the equation.  I'm pretty sure I remember reading something that stated the dimple pattern and size of the dimple has an impact on spin and how wind effects its flight.

[saevel25]

well dimples are suppose to decrease wind resistance, i think the physics behind that is that the dimples decrease surface area for the wind to come in contact with while maximizing surface area for contact with the golf club. So its basically trying to find that imbetween zone for control. But it doesn't effect generally how the wind effects the ball. If a ball is hit into the wind, head wind, it effects the ball the same as a smooth ball, just the intensity of the effect is different.