very stupid question

[Dimis]

please bare with me im sure this is a very silly question but i have to see if there is an answer

i was watching mythbusters last night (rerun of last weeks episode) and saw the golf ball divited car

it got me to think why hasnt anyone dimpled a bullet for better aerodynamics?

do you think it would help at all?

would you get a better BC?

or am i just completly off my rocker?

 

[FMJMIKE]

So.....How many beers so far tonight ???

 

[Nugilum]

No, I believe it would be detrimental to accuracy.

 

[xmanpike]

I'm going to guess it has something to do with thr golf ball being round and the fact that rifling spins the bullet anyhow.

 

[Beelzy]

Dimpling a bullet would ruin the BC (ballistic coefficient).

 

[Dimis]

seriously guys no beer

and the car wasnt round either

so you dont think that a properly designed bullet with dimpling could ever be effective?

 

[Extremely Pro Gun]

haha 000 buckshot could be dimpled but youll loose mass on the load.

 

[Grizfire]

A golf ball also spins, but it does so backwards (unless I hit the ball, in which case who knows what it does), while a bullet spins around an axis in the direction of travel.

 

[Mal H]

Dimpling on less-than-aerodynamically shaped objects helps them travel through air at high speed by breaking up and therefore lessening the eddy current in the air flow at the trailing edge of the object. In other words, it tends to lessen the partial vacuum in the rear that can drag on the object.

Bullets, rockets, most aircraft, etc. would not benefit much if at all from dimpling.

 

[Hud]

Boat tail bullets have the same effect.
I have been thinking of taking a ball-peen hammer to my Camry.
Note to self:Re-think this when sober

 

[545days]

They call the dimple a hollow point...

Actually, if I recall my gas dynamics class correctly, dimples have no effect on the drag coefficient of objects traveling faster than the speed of sound.

 

[Sport45]

dimples have no effect on the drag coefficient of objects traveling faster than the speed of sound.

Bingo! Air can't move faster than the speed of sound so supersonic bullets aren't dragging a "wake" of air with them anyway. They are pushing the air to the side.

 

[9mmepiphany]

it doesn't work on F-1 cars either.

the original idea was a rough texture like shark skin...which helps a shark glide through water...the texture on sharks is actually directional

 

[Cosmoline]

I've read a thread about doing this to blackpowder roundballs. Apparently it does seem to help. Doubt it would do much for a modern spitzer.

 

[griz]

Golf balls and muzzle loader round balls spin on different axis. That matters.

 

[Tedster]

Wait a minute. Golf balls aren' shot through a rifled barrel either, but I think they have a lot of spin, depending. So, what might happen if, or maybe it might be interesting with the old smoothbore cannon ball. They were always round, right? Maybe rough castings, don't know. I bet it was tried somewhere along the way. Did smoothbore cannon somehow spin the cannonball is a question.

 

[Wilson2]

Dimis,
I never thought of your question. However, upon reading it, I too was curious.

Good explanations guys, thanks.

P.S. The only stupid question is an unasked one.

 

[chuckusaret]

I always thought the dimples were to reduce drag a provide more surface area for lift.. I now know why my driver doesn't work well ,too much drag on the ball, need bigger dimples in the ball, Ha Ha.

 

[ghoster]

all i know is the dimples dont help my neighbors golf balls when they land in my feilds.

they havent out run one of my non dimpled rifle rounds yet.

 

[Husaberg Man]

"...please bare with me..."

Do we have to get naked before answering, and must we be bare with you?

 

[Dimis]

thanks for the scientific explainations it does make more sense now

and i am sorry for my spelling i have always been bad at that

 

[Husker_Fan]

When an object is travelling through a fluid (gas or liquid) there is going to be drag. If the fluid flow around the object is laminar (smooth streamlines), the drag is much higher than if it were turbulent (lots of little eddies). Golf balls are dimpled to create eddies in the fluid near the surface of the ball which results in a turbulent flow and reduces drag.

That's not an issue with bullets. You can tell if fluid flow is turbulent or laminar by the Reynolds number which is dependent on velocity. At the relatively high velocities of a bullet (compared to a golfball) the fluid flow will be turbulent regardless of the surface characteristics.

 

[SaMx]

Dimples are only really helpful on a bluff body at a subcritical reynolds number. for something like a car, plane, or bullet they would hurt more than they helped.

 

[GigaBuist]

Might help with paintballs...

 

[meef]

I don't expect that a dimpled a bullet would have better aerodynamics, but it sure would be cuter, wouldn't it?

Sort of the Shirley Temple Effect.

"Golly Mr. Jangles, lookit my feet per second!"