49 Comments

1. We actually do. Next time you fly on a commercial jet, look just aft (behind) the leading edge of the wing. You’ll see small “vortex generators” sticking up into the airflow. No, they aren’t pock-y dimples, but they do the same thing.

2. me too, need a brain adapted

3. We can do this, but we can’t figure out how to get bananas to hungry people in Africa… ………..hrm

4. Gripping stuff..

5. so wat if we applied this to a vehicle, or say a motorcycle helmet. would we benefit from it?

6. spacerip?

7. This is not particularly true. Most commercial jet wings are big enough to force the air into turbulent flow without vortex generators. Sometimes they are part of high lift configuration during take off and landing, but not during cruising. And their purpose is the exact opposite thing to reducing drag 🙂

8. Golf balls need the dimples because they are too small to create turbulent flow around them without additional disturbance by the dimples. Bigger objects don’t need it, because they cause turbulence on their own. And as always: Reality is even much more complicated than that! Turbulence is not generally a good or bad thing, as it consumes energy, that may gain you more than you invested, but its balancing on a blade!

9. this isn’t fun or interesting either. how do i keep getting here?

10. …why am I at this part of YT again?

11. …You were summoned here by the Force, maybe?

12. many missles also have these dimple, they are just longer and more stream line which will dictate the action of airflow around objects

13. I see you gave some technical info on this simulation about the time it took to run. Do you know if it’s a DNS or it has some turbulence modelling (LES for example)?

14. Fluids II. Classic example for separation.

15. The only explanation for me is that the dimples create some kind of air cushion around the ball and the air does not rub the entire surface of ball with high speed. Probably the interior air resistance is much lower than the the resistance between air and solid surface.
    It is not true that the dimples does not work by bigger object. Look on the Mythbuster experiment with dimpled car. Zipp patented bicycle disc wheels with dimples.

16. I am wrong! I found good explanation on aerospaceweb

17. Likely would not yield a markedly beneficial effect unless the car was operated at very high speed. But in theory, we think you’re right.

18. well, dont forget that the golf ball spins around an axis thru it, while a car is not, thats the reason dimples would not have the same effect, as a matter of fact not spinning, not round objects might become very unstable at high speeds.

19. mythbusters added dimples to a car which sped it up. Looks a bit ugly though

20. Wow.. the computer that did the CFD on this simulation must be quite powerful. My computer lags on simple simulations. Haha

21. The flow over the golf ball is first laminar, then turbulent. The dimples ‘force’ the transition from laminar flow to turbulent flow to occur in a shorter period. This is most apparent in small objects such as golf balls or model air crafts because the laminar region is very very short. In model aircrafts, for example, roughing up the leading edge is a common trick to attain the same result. In larger objects, such as trains or planes, the laminar region is so small it is negligible.

22. It really has to do with the shape of the structure. Drag is usually a combination of pressure drag and skin friction drag. A golf ball does not have to worry so much about skin friction drag since its length is relatively small, but bc its curvature is so pronounced, pressure drag is more significant. Thus, keeping the boundary layer stuck to the surface as long as possible reduces pressure drag. The dimples increase skin friction drag, but it is negligible compared to the pressure drag.

23. An airfoil (airplane wing) is much different. It’s smooth curvature and long length in and of itself reduces pressure drag since there is not so much space at the trailing edge that is at low pressure. However, because of its long length skin friction is more of an issue, so the goal is typically to maintain laminar flow as long as possible, which is the opposite of what is going on with this golf ball.

24. Excellent explanation. Thank you very much!

25. The benefits of roughening a surface on aerodynamic drag is really dependent on the shape of the object and the type of drag you are trying to eliminate.

26. Hello,
    I work directly with the golf courses and I sell my product direct to consumers (via internet etc) and also wholesale to courses etc.
    Thanks for your interest!

27. Hi Scott, im diving for balls in England UK but im having troubles with getting them into a bag or net while im down there. What advice would you give m on this? Thanks a lot.

28. how often to u go back to the same pond

29. how much do u sell them for

30. what do ya do with em?

31. can anyone tell me how much you can get for retrieved golf balls?

32. Is this the first time ever diving at this course? How often do you cycle through a course, I imagine it takes years for a water hazard to accumulate that sort of volume

33. I am a wholesale buyer…how can I get in touch with you to talk about buying your supply?? Thanks.

34. How deep on average are the water holes you dive in Scott??
    . . . and does your air line compressor take much maintenance? Cheers!

35. Dang and I thought the 1200 golf balls I received in about 5 hours one day with my ball retriever was a lot…. Apparently not!

36. i find this intresting….

37. i find this intresting.

38. i want to start the same job i already sell to a company but i buy from people that work on courses what equipment do you recomend for me to buy thanks for reading and good luck find them all

39. Hey scott,
    I wanna do this as a profession. I always wondered how nervous are you about getting bitten by stuff. Do you have a bite kit with you? Have you thought about wearing gloves?

40. do you ever feel turtles like snappers

41. is there any way you can give me a giant bag of assorted golf balls like those for like $100

42. Thanks for posting. As Arnie might say … veeery interesting….. but wet!

43. That’s incredible how many golf balls u found!

44. omfg you are my hero

45. Thumbs up if your the main supplier of his findings!

46. It all looks like great fun except for the water being murky. That’s kind of a deal breaker.

47. i always wondered what it would be like to do this! I wonder what the profit margin is!!

48. Thanks for putting the water safety message at the end. Very classy.

49. Ive watched this video like 10 times i just in joy it

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