Lynne Kiesling
How cool is this? Purdue engineering researchers have made major progress on a new internal combustion engine design, using variable valve actuation. One remarkable innovation in this research is removing the connection between the crankshaft and the camshaft, which is what drives the pistons up and down. This design has been at the core of engines since the late 18th century, and finding a way to create work without that connection is a true breakthrough. It also means that the pistons can be tuned independently, and the ignition will be controlled with electronic sensors and software algorithms, which makes the engine more flexible in terms of fuel mix and can reduce engine wear and depreciation as well.
The concept, known as variable valve actuation, would enable significant improvements in conventional gasoline and diesel engines used in cars and trucks and for applications such as generators, he said. The technique also enables the introduction of an advanced method called homogeneous charge compression ignition, or HCCI, which would allow the United States to drastically reduce its dependence on foreign oil and the production of harmful exhaust emissions.
The homogeneous charge compression ignition technique would make it possible to improve the efficiency of gasoline engines by 15 percent to 20 percent, making them as efficient as diesel engines while nearly eliminating smog-generating nitrogen oxides, Shaver said.
This improved combustion efficiency also would reduce emission of two other harmful gases contained in exhaust: global-warming carbon dioxide and unburned hydrocarbons. The method allows for the more precise control of the fuel-air mixture and combustion inside each cylinder, eliminating “fuel rich” pockets seen in conventional diesel engines, resulting in little or no emission of pollutants called particulates, a common environmental drawback of diesels.
The variable valve actuation system makes it possible to “reinduct,” or reroute a portion of the exhaust back into the cylinders to improve combustion efficiency and reduce emissions. The system also makes it possible to alter the amount of compression in the cylinders of both conventional and HCCI engines and to adjust the mixing and combustion timing, allowing for more efficient combustion.
This is a good example of why focusing all of our research resources on technologies other than the internal combustion engine is ill-advised. Technology does make leaps, but it doesn’t usually make the dramatic platform leaps that would be the equivalent of the leap from internal combustion to hydrogen fuel cell. The hybrid engine and the variable valve actuation engine are two examples of incremental innovations on an existing technology platform that produce different outcomes from the standard engine platform, in terms of energy use and emissions, but are still essentially internal combustion engines. These innovations on the existing engine platform can enable us to meet our energy and emission objectives without having to wait for the next platform to evolve into a commercial product.
HT to Slashdot for the link.
The fact is that the internal combustion engine has been becoming more efficient at the rate of about 1% per year for decades. Slow and steady improvement has been the trend. Variable valve actuation is one way that automakers have been improving efficiency (simpler systems that the one at Purdue).
The problem, if this can be called a problem, is that the automakers have been using this gain in efficiency to produce higher horsepower engines that get the same mileage. They have also used the efficiency to allow heavier, more feature packed, safer automobiles that get the same mileage.
And Barack Obama is wrong, the Japanese have been engaged in a horsepower war just as much as Detroit. How else can you explain a Honda Accord with 240 horsepower that weighs well over 3000lbs? The original Accord weighed 2000 lbs and had 100 horsepower. That’s progress!
The fact is that the internal combustion engine has been becoming more efficient at the rate of about 1% per year for decades. Slow and steady improvement has been the trend. Variable valve actuation is one way that automakers have been improving efficiency (simpler systems that the one at Purdue).
The problem, if this can be called a problem, is that the automakers have been using this gain in efficiency to produce higher horsepower engines that get the same mileage. They have also used the efficiency to allow heavier, more feature packed, safer automobiles that get the same mileage.
And Barack Obama is wrong, the Japanese have been engaged in a horsepower war just as much as Detroit. How else can you explain a Honda Accord with 240 horsepower that weighs well over 3000lbs? The original Accord weighed 2000 lbs and had 100 horsepower. That’s progress!
Howdy, Cuzz!
Yeah, those 6-cylinder Honda Accords are wonderful to drive! You’re so right… They’re not gas-sippers, but they’re awesome machines for the money. For the fun and the power they get good gas mileage and are pretty clean, but this is not real conservation. We’re way up on the power curve with these cars. I’ve been driving Honda Accords since 1979, so I’ve experienced it at various points along the way.
So, it boils down to a revealed preference issue -with these new, more efficient motors we can have either:
1) Lower fuel consumption for the same car, or:
2) More car for the same fuel consumption.
It appears that exercising free will, people are making the choice less favored by the enviro nanny-staters.
BTW, many of these advances are because of improvements in microelectronic control systems. The idea of solenoid-actuated engine valves, whose lift and duration could be infinitely customized and varied, and not mechanically linked to a camshaft lobe, has been around for a long time. The biggest issue has been implementing it reliably and economically.
So, it boils down to a revealed preference issue -with these new, more efficient motors we can have either:
1) Lower fuel consumption for the same car, or:
2) More car for the same fuel consumption.
It appears that exercising free will, people are making the choice less favored by the enviro nanny-staters.
BTW, many of these advances are because of improvements in microelectronic control systems. The idea of solenoid-actuated engine valves, whose lift and duration could be infinitely customized and varied, and not mechanically linked to a camshaft lobe, has been around for a long time. The biggest issue has been implementing it reliably and economically.
D.O.U.G.,
Allow me to “pick a nit”. Engine technology advances improve efficiency. Conservation is “doing less” or “doing without”. Driving a more efficient vehicle the same mileage each year as you previously drove a less efficient vehicle reduces fuel consumption as a result of the higher efficiency. Driving a vehicle of any efficiency fewer miles each year also reduces fuel consumption, as a result of the decision to conserve. Driving the more efficient vehicle more miles each year, because it can travel the additional miles at the same cost (same fuel consumption) as the less efficient vehicle travelled the fewer miles offsets the efficiency gain with negative conservation. This has been the history of the CAFE standards.
The government has not been successful in convincing us that we all want to drive “upholstered roller skates”, “skippy scooters” or Segways, no less bicycles. The ability to achieve 26 mpg highway in a Cadillac DTS with a Northstar V8 engine results in comfort without (or with minimal) guilt. The success of the Toyota Highlander hybrid, even at a $7,000 premium, suggests that we still really want both sportiness and utility in our SUVs. The market is responding to “what we want to buy” better than we are responding to the “nannys” telling us what we should buy. Imagine that!
D.O.U.G.,
Allow me to “pick a nit”. Engine technology advances improve efficiency. Conservation is “doing less” or “doing without”. Driving a more efficient vehicle the same mileage each year as you previously drove a less efficient vehicle reduces fuel consumption as a result of the higher efficiency. Driving a vehicle of any efficiency fewer miles each year also reduces fuel consumption, as a result of the decision to conserve. Driving the more efficient vehicle more miles each year, because it can travel the additional miles at the same cost (same fuel consumption) as the less efficient vehicle travelled the fewer miles offsets the efficiency gain with negative conservation. This has been the history of the CAFE standards.
The government has not been successful in convincing us that we all want to drive “upholstered roller skates”, “skippy scooters” or Segways, no less bicycles. The ability to achieve 26 mpg highway in a Cadillac DTS with a Northstar V8 engine results in comfort without (or with minimal) guilt. The success of the Toyota Highlander hybrid, even at a $7,000 premium, suggests that we still really want both sportiness and utility in our SUVs. The market is responding to “what we want to buy” better than we are responding to the “nannys” telling us what we should buy. Imagine that!
i am an automotive student in the university of eastern africa baraton. i would wish to engage in your discussions. pleas give me more details on how to get into chats with you or more.
Thanks in advance
valve,erie valve,pcv valve,r diff valve,red valve,
valve,erie valve,pcv valve,r diff valve,red valve,
valve,erie valve,pcv valve,r diff valve,red valve,