| From: Andrew Barker | 25/10/2001
11:31:20 |
| Subject: Flight of a golf ball | post id:
470716 |
| A dimpled golf ball travels a
greater distance than a smooth golf ball (original golf balls were
smooth). Why isn't this dimple principle apllied to more objects that move
through fluids? Racing cars? Aeroplanes? Boat hulls? Could someone explain
this to me? | |
| From: New White Froot Loop | 25/10/2001
11:34:25 |
| Subject: re: Flight of a golf ball | post id:
470722 |
| 1/ They don't spin. 2/ Their surface to mass ratio is much lower. | |
| From: ferrett ® | 25/10/2001
11:35:46 |
| Subject: re: Flight of a golf ball | post id:
470723 |
It's difficult to explain without a diagram, but basically the dimples help the rotating golf ball to split the incident airflow, below the centre of mass of the ball, so that air passing over the top of the ball has to go a greater distance than the air over the bottom. (Hence produces lift.) This effect only works for rotating bodies, so is not applicable to racing cars etc. There have been previous threads. Someone will probably direct you there. (I would, but my computer skills are rudimentary.) | |
| From: Greg Mc ® | 25/10/2001
13:18:49 |
| Subject: re: Flight of a golf ball | post id:
470979 |
| You are looking for the
phenomenon known as the "Magnus effect". It is the principle by which top
spin or back spin or side spin effects the "flight" of spinning objects
such as balls or cylinders. | |
| From: Laser | 25/10/2001
17:36:07 |
| Subject: re: Flight of a golf ball | post id:
471415 |
| The golf ball technology is used
in the atuo industry.More on this down the page. The dimples work like this: --------------------------- The dimple traps a certain volume of air that will spin and slay in the dimple. The golf ball will will have much less surface friction now. As the ball travels through the asmoshpere, the atmosphere will have friction on the undimpled area, and the spinging air in the dimple. conculsion ----------- The atmosphere is not in contact with the whole surface area of the moving golfball. The golfball will travel further because there is less friction. THIS GOLFBALL TECHNOLOGY IS USED IN THE AUTO INDUSTY Performace manifolds have very small dimples, to do the same thing. The very best racing vales ,made by MILODIN use this technolgy . They call this valve a swirl polished valve.They grind find lines perpendicular to the air flow.The traped air swirls in the scratches of the valve. On the diagram, can you see that you will have little friction where the atmosphere comes in contact with the traped air in the dimple? gee me english is bad. | |
| From: Laser | 25/10/2001
17:47:36 |
| Subject: re: Flight of a golf ball | post id:
471430 |
| We used this technology in the
Olympics. The speedo swimming suits, that we wore, traped air on the suits surface. That way, we only had water to air friction on some of the parts of the swimming suit. | |