Goodyear’s New Concept Tires
Tire technology has always been something of a black art – even the word “vulcanization” refers to a pagan god long associated with sorcery and the fiery underworld. Prior to having a rubber-hardening process named after him, Vulcan was also the patron deity of alchemy – the practice of “transmuting” one substance or energy into another. Today’s chemistry and physics owe much to this “black art;” the First Law of Thermodynamics, for example, is little more than a restatement of alchemy’s “principle of equivalent exchange.”
Nobody’s saying tire tech is a “black art” in the sense of being occult – more in the respect that no matter how much they’ve advanced in the last century, tires have always looked pretty much the same, and performed the same job. The black art of tire development has long put improvements under the surface, with outward revolution the exception and gradual evolution the rule.
But every so often, something comes along to truly revolutionize everything we believe about what a thing is or what it does.
Meet the Goodyear BH03 Thermoelectric and TripleTube tires, introduced in Geneva last week.
Continue reading to learn more about Goodyear’s new concept tires.
The TripleTube Tire
What’s in a name? Apparently not much for the TripleTube, which has four independent air chambers. More on the rationale in a moment, but before that: This isn’t Goodyear’s first foray into multiple-tube tires. In fact, the TripleTube could almost be seen as a direct evolution of their very first.
Back in 1963, Goodyear introduced the Double Eagle, the “safety tire” with a “built-in spare.” Effectively the granddaddy of all run-flat tires, the Double Eagle used separate air chambers near the tread and rim to ensure that in the event of a puncture or blowout, the tire wouldn’t completely deflate. These safety tires were standard equipment in NASCAR for a long time, and one reason you still see “Goodyear” all over the series today.
The TripleTube, though, works a little differently than the old Double Eagle.
Like the Double Eagle, it has a large “main” air chamber nearest the rim. This chamber holds the majority of the air, and supports the car. Like the Double Eagle, it also has an outer air chamber close to the tread. However, the TripleTube’s outer chamber has two dividing walls running all the way around, effectively dividing it up into three separate chambers. One runs along the center of the tread, and two others flank it toward the edges.
A good idea in terms of safety, seeing as how it would be almost literally impossible to get a flat. But the TripleTube’s real party trick comes when you combine it with fast-reacting tire inflation systems.
Assuming you have three independent air channels, and a means of varying pressure quickly, the TripleTube’s construction would allow a tire pressure control system to instantly change the size and shape of the tire’s contact patch. From Goodyear’s press release, the TripleTube would offer three different modes:
• Eco/Safety Position: Offers reduced rolling resistance through optimized stiffness distribution. It also provides dry braking through a wide footprint in contact with the road.
• Sporty Position: Gives drivers dry handling through optimized contact patch using active conical shape.
• Wet Safety Position: Provides high aquaplaning resistance, through a raised tread in the center of the tire, leading to a bigger tire diameter resulting in a narrow and long footprint.
Less tire in contact with the road makes for better fuel economy; that’s why economy cars tend to have skinny tires. A long, skinny footprint also enhances traction on wet, snowy and icy roads, which is why specialized rain and winter tires are equally skinny. By inflating the tire’s center-outer chamber more than the edge chambers, you get a cone-shaped tread instead of the dead-flat tread you’d need for straight-line acceleration and braking on dry roads.
If you could get air pressure to respond fast enough, you could even deform the angle of the contact patch for better handling. In this way, the tire could effectively vary its own camber angle on the fly, allowing the tread to “lean into turns” like a motorcycle.
Could you do that without the crazy “fin design” tread pattern of the show tire? Probably. But it looks cool and futuristic, which helps when you specialize in doing things people can’t see.
Of course, a lot of this depends on having an onboard air system to control the tires. It sounds pretty simple in theory, but the devil is in the details, and complications start adding up quickly when you try to take this system to its outer limits. It’s not just a matter of varying air pressure quickly enough to keep up with the car’s handling demands; that alone is difficult, but it can be done. It’s that you’d have to do that three times for each tire, so you’d end up with an air system running no fewer than 12 different air channels, which would have to be controlled in real-time. Or, even if you completely ignore the two outer channels, you’d still end up with four separate air channels, just to enable the three static driving modes Goodyear proposes.
Are these insurmountable problems? Nope. Not at all. It’s just that without some investment on the part of automakers to develop and install control systems, the TripleTube won’t reach its full potential.
All the same, it does offer some massive advantages in terms of fuel economy and performance, and it’s probably is only a matter of time before manufacturers get behind it. Fuel economy standards are tightening daily, and gains aren’t getting any easier or cheaper to come by. Even if the TripleTube offered only a 10 percent increase in fuel economy, it would still be a godsend for manufacturers. Especially if they’re already using tire inflation/deflation systems, which are getting more common by the day. From there, it’s a pretty small step to doubling the number of air channels and making the TripleTube a practical reality.
It’s been a long road from the Double Eagle to the TripleTube, from making tires safer to making them better at every aspect of their jobs. But alchemists are never content to turn lead into slightly better lead. The endgame is always, of course, gold.
The Bh03 Thermoelectric Tire
While the TripleTube is undoubtedly an impressive evolution, the BH03 may represent a revolution in terms of the very job a tire performs. Until now, a tire’s only real job has been to put power to the ground and not get destroyed doing it. The BH03 recovers power from the ground in the form of heat, and returns it to an electric vehicle’s battery pack as electricity.
The idea of thermoelectric power generation is nothing new. German physicist Thomas Seebeck first observed the phenomena all the way back in 1821, and we’ve been trying to figure out how to use it ever since. Actually, we’ve been trying to understand it ever since. It’s only been in the last couple of years, thanks largely to a study completed by Ohio State University in 2012, that the “Spin Seebeck Effect” was understood and developed well enough to see applications in the real world.
The gist of it is this: When heat moves through a magnetic conductor, from hot side to cold, it produces an electric current. The science behind that is complex, and still not entirely understood. But it works, and the 2012 Ohio University experiments uncovered a way to amplify the Spin Seebeck effect a million times over.
Previously, the best room-temperature thermoelectric materials could eke maybe a few nanovolts per degree of temperature increase from the thermoelectric effect. That’s barely enough to measure, let alone recharge a car battery.
Now it’s up to a few millivolts per degree of temperature change. Still not an enormous amount, but do the math: 4 mV times a 60 degree temperature differential is almost a constant 1 volt of current. Again, not a huge amount, and certainly not enough to recharge a car’s batteries as you drive. There’s just not enough heat produced, and the temperature differential isn’t that great.
Goodyear knows that, though, which is why the BH03’s tread looks so…weird. Unlike the TripleTube’s oddball tread, which is more for show than anything else, the BH03’s tread blocks are engineered something like little radiators. Those large, dark sections dissipate heat, and the flat sections gather it. That keeps thermal energy moving through the tire’s thermoelectric elements, increasing the temperature differential and the amount of power produced.
Of course, all of this is in its infancy – even if Goodyear multiplied the power output by ten, 10 volts still isn’t much. That’s why, as of now, the BH03 is still a concept and in no immediate danger of being put into production. But it does presage a change in the way we think about the way our cars use and waste energy, and shows how the relentless march of technology makes its way into the most unexpected places.
Certainly, this isn’t the first attempt at energy recovery through movement. There’s a patent from 2001 for a wheel-mounted energy recovery system that uses changes in air pressure. And magnetic suspensions are practically generators waiting to happen, capable of producing some significant voltage from wheel and tire movement. It’s an ever-expanding field, and we’re sure to see dividends from it soon. Thermoelectric technology, even if it never sees use in tires, is almost certain to eventually find its way to engines and exhaust manifolds. The temperature differentials there can be over a thousand degrees, and that does count for something in terms of voltage. Assuming of course that we don’t find a way to amplify the Seebeck effect another million times over at some point.
Who knows? Divination is as black an art as any, including tire development and alchemy. Nobody could have predicted bacon-chocolate milkshakes a hundred years ago either, but here we are. So these tires are at present just concepts, but important ones.
Because if history tells us anything, it’s never to doubt the alchemists among us.