Browse Topic: Multifuel engines
Spark-ignition direct-injection technology existed since about 1930 for the primary purpose to give multifuel capability over what the compression-ignited diesel engine could provide. In subsequent decades development of multifuel engines continued both as higher-compression-ratio “spark-ignited diesel” and moderate-compressionratio stratified-charge engines. Global events in the 1960-1970’s, namely the oil embargo, oil-supply crises, and the passage of the U.S. Clean Air Act intensified interest in such engines. The military and large commercial fleet operators were particularly focused on efficiency and multifuel capability over concerns for fuel supplies. Automobile manufacturers were focused on gasoline-fueled efficiency and the potential to reduce engine-out legislated NOx emissions with the stratified-charged combustion systems. In this paper the major direct-injection spark-ignited stratified-charge concepts pursued during the 1970-1980’s are reviewed at a high level, and
The three-year, $30 million Multi-fuel MultiAir R&D program with the U.S. DOE is nearing completion. Here's what Chrysler Powertrain engineers have learned as they try to achieve a 25% fuel-efficiency gain. Chrysler's ambitious program to demonstrate a 25% combined city/highway FTP fuel-efficiency improvement in a production minivan has entered the final and most critical phase of development. With dyno testing of the advanced 2.4-L dual-fuel inline four successfully completed, the powertrain next must prove itself under real-world operating conditions. “So far, we're very happy with this program,” Chris Cowland, Chrysler's Director of Advanced Engineering and SRT Performance, told AEI. “But now comes the biggest challenge-making the engine fully drivable in a car, while meeting Tier 2 Bin 2 emissions levels and feeling like a normal engine to the end customer. And we have to do it by April.”
The editors compiled this top 10 of the past year's most significant automotive-engineering articles based on the online activity of our readers. Managerial responsibility is key to earning a fat paycheck, according to the results of a first-of-its-kind global survey of automotive, aerospace, off-highway, commercial vehicle, and other mobility engineers. “The biggest impact on an engineer's compensation is how many people you supervise, and the differential between managing five to 10 persons or managing 10 or more engineers was as much as $20,000. That's a real eye-opener,” said Bill Cariello, Manager of Web Strategy/Operations for SAE International, during an SAE Convergence 2010 press conference on the survey Oct. 19. SAE's mobility engineering salary survey of SAE members and nonmembers was compiled from online questionnaires completed by 5288 engineers working across the globe. “There is quite a substantial pay difference between an engineer having a bachelor's degree and a
In this paper we discuss in detail an algorithm that addresses cylinder-to-cylinder imbalance issues. Maintaining even equivalence-ratio (θ) control across all the cylinders of an engine is confounded by imbalances which include fuel-injector flow variations, fresh-air intake maldistribution and uneven distribution of Exhaust Gas Recirculation (EGR). Moreover, in markets that are growing increasingly cost conscious, with ever tightening emissions regulations, correcting for such mismatches must not only be done, but done with no additional cost. To address this challenge, we developed an Individual Cylinder Fuel Control (ICFC) algorithm that estimates each cylinder's individual θ and then compensates to correct for any imbalance using only existing production hardware. In our production-bound algorithm, modeling and control of the cylinders' dynamic θ was performed using a single switching oxygen sensor. Our ICFC algorithm was developed on a 2.4-l four-cylinder DOHC engine and it is in
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