(Page 2 of 2)
Another important difference from previous designs is that the fuel injector is positioned centrally in the head of the cylinder, rather than in the side. This enables fuel and air to mix better, though it means that the injector is located at the hottest part of the engine and so requires improved water flow to keep it cool. An added benefit of better combustion is lower amounts of unburnt fuel in the exhaust, resulting in fewer hydrocarbon emissions.
Lotus Engineering and Continental Powertrain have already adopted the technology in a low-carbon concept car. A three-cylinder, 1.5-liter engine based on the combustion concept has been fitted to the Opel Astra and shown to cut carbon dioxide emissions by 15 percent compared to the Astra's standard, 1.8-liter, four-cylinder engine. At the same time, the concept car produces a 36-percent increase in torque and a 14-percent increase in power output.
According to Geraint Castleton-White, power-train leader at Lotus Engineering, the outcome is a car that emits 140 grams or less of carbon dioxide per kilometer. In 2007, cars sold in Europe averaged 158 grams of carbon dioxide per kilometer; proposed legislation in the European Parliament would require cars to meet standards of 130 grams per kilometer by 2012.
"We have had tremendous interest from manufacturers around the world and the concept will be in production in the future," says Castleton.
The prototype engine is more cost effective than other direct-injection, "lean burn" engines, because it avoids the need for expensive equipment to trap nitrogen oxides, he says.
John Heywood, professor of mechanical engineering at MIT, isn't surprised by the improvements. "There has been a nearly linear improvement in performance of internal combustion engines over the last couple of decades or so," he points out. "We need to pursue all possibilities that look promising." But he suggests there are other potential ways of increasing engine efficiency, such as reducing friction, which might end up being more cost effective. "There are questions over the long-term market attractiveness of variable-valve technology," he says.
A hydraulic hybrid technology lets trucks burn a third less fuel than they normally would.
Free-piston engines could be used to generate electricity as efficiently as, and less expensively than, fuel cells.
Electromagnetic Valve Actuator
Why add complexity and waste energy with a hydraulic system?
A fully flexible electromagnetic valve actuator was recently recognized by the R&D Magazine (http://www.rdmag.com/) as one of the 2008 R&D 100 Award Winners. For details: http://www.engineeringmatters.com/indexproj.htm
It has been known for quite some time that if you provide complete mixing of fuel plus oxidant (i.e. homogeneous mixture) you can get efficient complete combustion. Modern steam engines and gas turbines do this routinely.
Instead of adding complexity simply attack the base problem. Premix the fuel and oxidant, gaining control not only of the ratios of the two constituents, but of the absolute quantity.
This approach will free the designer to consider the quantity of constituents question in more detail involving the cylinder compression ratio and various ignition strategies such as diesel operation and catalyticly initiated combustion.
Continuing to improve a flawed approach doesn't lead to better technology only a more expensive one.
Big advance? Not so obvious...
This is only natural evolution based on research work, another step. Everyone see the problem with electro-magnetic valves, if an electrical problem comes during normal use? Not nice to have an engine broken by a simple electrical problem ! Costs ? Why engineers don't explore more the mechanical solutions? I GIVE my R-VVA valvetrain system for development to a real interessted Company, this is the most simply variable valvetrain system, and permits continuous full variation in all parameters of valves work, elimination of throtle bodies, better intake and exhaust ducts design, increased power, larger torque power band, half-intake cycle for low and medium charges and rotational speed, etc. After we can make a very flexible engine according necessities, sure to have an more efficient and less polluting powertrain. The dream of all is to have an engine with the torque of a truck and at same time the power of an sport car? Or not?
Until today, the most advanced desmodromic variable valvetrain is from Pattakon-Greece, but the most simply variable valvetrain is my REVERSE-VVA system.
What I see is not the application of the best technologies, but by other side, the technologies who serves a few interests of some people.
In conclusion, I have seen this: the people involved around Automotive Industry development, only is focused in solving his own problems than they create; they not consider a broken with past and the implementation of completely new solutions and technologies.
Apart from general crisis, another problem in Automotive Industry is his own slow advance in innovations concerning Powertrain. This Industry has more than 10 years of retard, in technology.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
Our list of the 50 most innovative companies, including the following:
On Twitter
Become a Fan on Facebook
Subscribe to the Feed
jpm000001
8 Comments
mgp?
So does this 15% less fuel mean the engine would go from 30 mpg to 34.5 mpg? Doesn't sound too dramatic. But still, a tip of the hat to the researchers.
Let's forget about these gas engines --electric motor efficiency blows them out of the water -- and do more research into better batteries.
Reply
Siphon
152 Comments
Re: mgp?
Agreed. A 15% reduction is not exactly 'sipping'. That would have to be more like 80-90% reduction. Oh wait, that's impossible!
Electric motors and batteries it is. Thermodynamics says so. Still, an efficient generator for a series hybrid or series plugin hybrid would be very useful, so any research, even incremental, is of help.
Reply