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Towards a Better Understanding of Controlled Auto-Ignition (CAI™) Combustion Process From 2-Stroke Engine Results Analyses
Technical Paper
2001-01-1859
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Owing to its inherent high internal residual gas rate in partial load operation, the 2-stroke engine has been the first application to take benefit of the unconventional CAI™ (Controlled Auto-Ignition) combustion process. For a long time, the objective of the different research works on 2-stroke engines optimization was to eliminate its two main drawbacks leading to high emissions of unburned hydrocarbons and a poor fuel efficiency. The first one is the unstable running operation combined with incomplete combustion, especially at light load, The second one is fuel short circuit at medium and full load. From the end of seventies, an approach developed by Onishi from Nippon Clean Engine was to take benefit of an high amount of hot internal residual gases to help auto-ignition of the fresh charge. This solution has been further developed up to the industrialization on 2-stroke engines.
More recently, within the framework of the European 4-SPACE program driven by IFP, the CAI™ combustion process has been successfully applied to a 4-stroke engine, demonstrating its potential for near zero NOx emission levels combined with a significant fuel saving and thus reduction of CO2 emissions. This application was directly derived from 2-stroke engine analyses which can be considered as an useful tool to better understand this combustion process.
This paper presents several approaches to analyze this unconventional combustion process by combining 2-stroke engine trials on a dyno test bench with more advanced research and development tools such as 3D CFD and optical diagnostics. The fluid dynamical behavior in the cylinder during the scavenge process and the compression stroke was studied using 3D CFD and showed that the mixing level between the fresh charge and the internal residual gases is a key parameter to obtain and to control CAI™.
The experiments performed on an optically accessible engine allowed to make direct visualization of combustion and to show the outline of the zones of combustion from an initiation and development point of view. Results obtained by a Mie scattering technique allowed us to distinguish the distribution of fresh and residual gases during the scavenging process and the compression stroke in motored conditions. The application of this optical technique combined with direct combustion vizualisation gives more detailed information on the physical process, especially when studying the effects of certain parameters as the engine speed. The post processing of the images allowed notably to estimate the number of auto-ignition sites and the propagation mode of the combustion.
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Citation
LAVY, J., ANGELBERGER, C., GUIBERT, P., and MOKHTARI, S., "Towards a Better Understanding of Controlled Auto-Ignition (CAI™) Combustion Process From 2-Stroke Engine Results Analyses," SAE Technical Paper 2001-01-1859, 2001, https://doi.org/10.4271/2001-01-1859.Also In
References
- DURET P. DABADIE J.C. COLLIOU T. Application of IAPAC Fuel Injection for Low Emissions Small Two-Stroke Engines 4th SETC Conference - SAE 951785
- NUTI M. CAPONI D. The Development of a Propulsive Unit for Friendly Individual Commuting Vehicle SAE 991246
- COPLIN N. Simplification of Air Assisted Direct Injection via Performance Benchmarking SAE 9938065
- DURET P. LAVY J. VENTURI S. ALLEN C. SCIP Simplified Direct Injection for Low Emissions Small Two-Stroke Engines SETC 99 - SAE 1999 01 3289
- LAIMBOCK F-J. KLASNIC H. GRILC S. MEISTER G-F. DORFSTATTER M-J. AVL SDIS Mk.II -Low Cost Automotive FI Applied to 2-Stroke Engines for Future CARB-Regulations - SAE 9938040
- MORIYOSHI Y. MORI K. MORIKAWA K. TAKIMOTO H. Mixture Formation Analysis of a Schnurle-Type 2-Stroke Gasoline DI Engine SAE 2001 01 1091
- VENTURI S. LAVY J. DURET P. From Development to Industrialization of an IPAC Marine Outboard D.I. 2-Stroke Engine Paper 1780 - SETC 2001 Pisa
- LECOINTE B. LAVY J. DURET P. SINDANO H. WATSON A. EURO II Calibration of Direct Injection SCIP Technology on 50cc Two-Wheelers Paper 1784 - SETC 2001 Pisa
- STAN C. LEFEBVRE J.L. Development of a Direct Injection Concept for Two Wheelers Equipped with Two-Stroke Engines SAE 991248
- NAJT P.M. FOSTER D.E. Compression-Ignited Homogeneous Charge Combustion SAE 830264
- THRING R.H. Homogeneous-Charge Compression Ignition (HCCI) Engines SAE 892068
- AOYAMA T. HATTORI Y. MIZUTA J. SATO Y. An Experimental Study on Premixed-Charge Compression Ignition Gasoline Engine SAE 960081
- STOCKINGER M. SCHÄPPERTÖNS H. KUHLMANN P. Versuche an einem gemischansaugenden Verbrennungsmotor mit Selbstzûndung (Investigations on a gasoline Engine working with Self-Ignition by Compression) MTZ Motortechnische Zeitschrift 53 1992 2 80 85
- OPPENHEIM K.A. Pulsed Jet Combustion generator for premixed charge engines Patent 4,926,818 1990
- HIGELIN P. ROBINET C. MOUNAIM-ROUSELLE C. PAJOT O. MOREAU B. Proc. 15 th International Combustion Engine Symposium Seoul Korea July 13-16th 1999 395 400
- LAVY J. DABADIE JC. ANGELBERGER C. WILLAND J. JURETZKA A. SCHAFLEIN J. MA T. LENDRESSE Y. SATRE A. SCHULZ C. KRAMER H. ZHAO H. DAMIANO L. Innovative Ultra-low NOx Controlled Auto-Ignition Combustion Process for Gasoline Engines: the 4-SPACE Project SAE 2000-01-1837
- DURET P. LAVY J. Gasoline Controlled Auto-Ignition (CAI ™ ): potential and prospects for future automotive application IMechE Conference 21st Century Emissions Technologies 4 5 December 2000 London
- LAW D. ALLEN J. KEMP D. WILLIAMS P. 4-Stroke Active Combustion (Controlled Auto-Ignition) Investigations Using a Single Cylinder Engine with Lotus Active Valve Train (AVT) IMECHE 4-5 December 2000
- ONISHI S. JO SOUK HONG SHODA K. JO PAN DO KATO S. Active Thermo-Atmosphere Combustion (ATAC) - A New Combustion Process for Internal Combustion Engine SAE 790501
- NOGUCHI M. TANAKA Y. TANAKA T. TAKEUCHI Y. A Study on Gasoline Engine Combustion by Observation of Intermediate Reactive Products during Combustion SAE 790840
- ASAI M. KUROSAKI T. OKADA K. Analysis on Fuel Economy Improvement and Exhaust Emission Reduction in a Two-Stroke Engine by Using an Exhaust Valve 4th SETC Conference - SAE 951764
- ISHIBASHI Y. ASAI M. Improving the Exhaust Emissions of Two-Stroke Engine by Applying the Activated Radical Combustion SAE 960742
- DURET P. VENTURI S. CAREY C. The IAPAC Fluid Dynamically Controlled Automotive Two-Stroke Combustion Process IFP International Seminar 1993
- DURET P. VENTURI S. Automotive Calibration of the IAPAC Fluid Dynamically Controlled Two-Stroke Combustion Process SAE 960363
- GENTILI R. FRIGO S. ATAC and GDI in a Small 2 Stroke Engine SAE 9938028
- PETIT LAVY J. MONNIER G. MONTAGNE X. Speciated Hydrocarbon Analysis: A Helpful Tool for Two-Stroke Engine Development IFP International Seminar 1993
- IIDA N. Combustion Analysis of Methanol - Fueled Active Thermo-Atmosphere Combustion (ATAC) Engine Using a Spectroscopic Observation SAE 940684
- LAVY J. DURET P. IFP International Consortium Project on the Effects of Fuels and Additives on Controlled Auto-Ignition Consortium reports 1995-1997
- Shoji Hideo Amino Yasunori Hashimoto Shunsuke Yoshida Koji Saima Atsushi “Clarification of OH radical emission intensity during autoignition in a 2stroke spark ignition engine” SAE 982481
- LAVY J. RAUX S. ESTERLINGOT E. GUIBERT P. Thermodynamical And Optical Analyses of Controlled Auto-Ignition Combustion 2-Stroke Engines SETC 97 - SAE 972098 - JSAE 97 34 313