Abstract

The combustion chamber shape of an engine with high compression ratio, long stroke, high-quantity cooled EGR, and retarded intake-valve-closing specifications was optimized to increase the EGR limit and minimize unburned loss and time loss with the aim of enhancing the brake thermal efficiency of a stoichiometric gasoline engine. A piston shallow-dish shape was adopted to optimize the tumble center and the piston top surface distance from the spark plug, and the combustion chamber peripheral shape was optimized to minimize unburned loss. The resulting enhancement of the external EGR rate limit and increase in combustion speed reduced both time loss and unburned loss, and achieved a brake thermal efficiency of 45.2%.

References

1. (1) Alger, T., Mangold, B., Roberts, C., Gingrich, J.: The Interaction of Fuel Anti-Knock Index and Cooled EGR on Engine Performance and Efficiency, SAE Int. J. Engines 5(3), p. 1229-1241 (2012)
2. (2) Kishi, K., Satou, T.: The new Nissan high efficient 1.2L 3cyl GDI Supercharged Engine enables 95g/km CO2 Emissions and High Driving Performance, Forstschr Ber Vol Reihe12, 749 Bd2, p. 35-49 (2012)
3. (3) Sagawa, T., Fujimoto, H., Nakamura, K.: Study of Fuel Dilution in Direct-injection and Multipoint Injection Gasoline Engines, SAE Technical Paper, 2002-01-1647 (2002)
4. (4) Tagishi, R., Ikeya, K., Takazawa, M., Yamada, T.: Technology for Realization of Gasoline Engine Brake Thermal Efficiency of 45%, Honda R&D Technical Review, Vol. 27, No. 2, p. 1-11
5. (5) Ikeya, K., Takazawa, M., Yamada, T., Park, S., Tagishi, R.: Thermal Efficiency Enhancement of a Gasoline Engine, SAE Int. J. Engines 8(4), 2015-01-1263 (2015)

Author (organization or company)

• Masanobu TAKAZAWA（Automobile R&D Center）
• Tomoaki SASAGAWA（Automobile R&D Center）
• Atsushi OHTA（Automobile R&D Center）
• Noriyuki TAKEGATA（Automobile R&D Center）
• Taketo YAMADA（Automobile R&D Center）

Publication Information

Article of Honda R&D Technical Review Vol.27 No.2 (61 - 70)

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Citation Information