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The Effects of Charge Stratification on Nitric Oxide Emission from Spark Ignition Engines
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Abstract
Charge stratification has long been considered the best feasible means of burning overall weak mixtures. This offers the attractions of fuel economy and relatively low levels of pollutants emitted from the engine. In this paper, two idealised models of charge stratification are considered theoretically, with the emphasis on nitric oxide emissions.
The first model represents a linear variation of fuel-air equivalence ratio, from a fuel rich mixture of the first element to burn, to a fuel weak mixture of the last element to burn. The effects of the slope of the equivalence ratio to mass fraction burned and the mean value of the equivalence ratio on nitric oxide emissions are analysed and discussed.
The second model represents a step variation in the equivalence ratio, with two different zones each having a constant value of the equivalence ratio, and each being homogeneous within itself. The nearest to this model in practice is the double chamber engine, with a fuel rich primary chamber and a fuel weak secondary chamber. The theory analyses and discusses in detail the effects of the ratio of the two equivalence ratios, the ratio of the primary to secondary charge mass, and the overall mean equivalence ratio on exhaust emissions of nitric oxide. Furthermore, the intake and compression strokes of such a system prior to ignition are considered, showing the continuous variations of equivalence ratios.
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Citation
Watfa, M., Fuller, D., and Daneshyar, H., "The Effects of Charge Stratification on Nitric Oxide Emission from Spark Ignition Engines," SAE Technical Paper 741175, 1974, https://doi.org/10.4271/741175.Also In
References
- Simko A. Choma M. A. Repko L. L. “Exhaust Emission Control by the Ford Programmed Combustion Process-PROCO.” SAE Transactions 81 1972 paper 720052
- Mitchell E. Alperstein M. Cobb J. M. Faist C. H. “A Stratified Charge Multifuel Military Engine-A Progress Report.” Paper 720051 SAE Automotive Engineering Congress and Exposition Detroit January 1972
- Miyake M. “Developing a New Stratified Charge Combustion System with Fuel Injection for Reducing Exhaust Emissions in Small Farm and Industrial Engines.” SAE Transactions 81 1972 paper 720196
- Hussman A. W. Kahoun F. Taylor R. A. “Charge Stratification by Fuel Injection into Swirling Air.” SAE Transactions 7 1963 421 444
- Newhall H. K. El-Messiri J. A. “A Combustion Chamber Concept for Control of Engines Exhaust Air Pollutant Emissions.” Combustion and Flame 14 1 February 1970
- Newhall H. K. “A Combustion Chamber Designed for Minimum Engine Exhaust Emissions.” SAE Transactions 79 1970 paper 700491
- Bascunana J. L. Conta L. D. “Further Research on Charge Stratification.” SAE Transactions 75 1966 paper 660095
- Eshelman R. A. “VW's Stratified Charge Engine Coming?” Automotive Industries December 1973
- Wimmer D. B. Lie R. C. “An Evaluation of the Performance and Emissions of a CFR. Engine Equipped with a Prechamber.” Paper 730474 SAE National Automobile Engineering Meeting Detroit May 1973
- Daneshyar H. Watfa M. “Prediction of Nitric Oxide (NO) Concentration in Spark-Ignition Engines.” Combustion and Flame 21 1973 395 398