Amy Williams's gold medal skeleton helmet (with vortex generators)

[winkosmosis]

Anyone hear about the controversy over the little ridges on the British skeleton gold medalists's helmet? The US and Canada filed protests, but it was ruled that the ridges are an "integral part of the helmet".

I guess vortex generators do work

Did helmet make a difference in skeleton win? - Fourth-Place Medal - 2010 Olympics Blog - Yahoo! Sports

[luvit]

these are the same divits i hammered into my car. that's why i acheive 70mph @ 80mpg.

[Christ]

LOL.

They could test the idea... I bet the Mythbusters would take a crack at it.

And who ever said that VG's don't work? They serve a purpose, when placed and sized properly for the application. That's been said here numerous times. They're not an answer to ideal shapes, but they're a good band-aid for an uncurable situation.

[bgd73]

707s have had vortex generators in the horizontal stab for 50 years..they do indeed work to change a surface, pressure. As little as a helmet, it may be hard to measure...just go with it as common sense.

[RH77]

Originally Posted by bgd73

707s have had vortex generators in the horizontal stab for 50 years..they do indeed work to change a surface, pressure. As little as a helmet, it may be hard to measure...just go with it as common sense.

I thought the same -- most passenger airliners have these on various surfaces: most visible to passengers are on wing tops.

I thought a lot about this, but a small mod like this doesn't come close to the athlete's overall ability (if there's a concern about an unfair advantage, although judged legal).

As far as vehicle mods, they would have to be very strategically placed to even offer a minimal advantage.

RH77

[tasdrouille]

Originally Posted by winkosmosis

I guess vortex generators do work

Placement and size are critical for VGs to work. So with the eyeballing installation of VGs and no real way to measure the impact, the effectiveness is up in the air.

You can bet that helmet was designed in a wind tunnel.

[thatguitarguy]

That helmet doesn't sport big fins sticking up out of it, and supports my theory that you can trip the boundary layer sufficiently without sticking up past it.

People on this site that have experimented with VG's have talked about noise, and I think that if you're creating enough drag to generate that much sound over background noise that it's probably too much. I doubt that the ridges in that helmet created very much noise - they may very well have quieted some noise - and when you are wearing something over your entire head you can tell.

[wdb]

When athletes attain the level of fitness and skill necessary to contend for gold, little stuff does indeed matter. Yes their ability utterly overwhelms any advantage a few fins might make, but since their skill levels are comparable the playing field is level in that regard.

If you look at the times, you can clearly see the impetus for protesting the helmet.

Amy won every heat of the 4-heat event. She won by .3 seconds or more each time (except the last heat which was very close). That's 0.5% or more of each 53-54 second total run time. 2nd through 5th places tended to be hundredths of seconds apart, not tenths.

I also doubt that the helmet made the difference, but if I was an opposing coach I would most certainly have protested.

[winkosmosis]

Why are aero features like this allowed? Isn't there a standard helmet shape? Is any helmet OK as long as the parts are all integral?

[thatguitarguy]

I don't know the exact rules, but I do know that helmet shapes have been very controversial in other events, especially skiing and cycling. Apparently, once you figure out the placement of VG's or boattails, then all you have to do is mold the helmet to incorporate those shapes into the structure so that they are not just "stick-ons". Speed skiing and time-trial cycling have seen some pretty radical shapes - much moreso than the little ridges on Amy's helmet. Open cockpit car racing has had some weird looking VG's on drivers helmets, but this has been more to reduce buffeting than to increase speed.