Variations of swirl center according to evaluation position in steady flow bench of SI engine
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In this study, the variations of swirl center according to evaluating position have been investigated in a steady flowbench of SI engine. For the experiments, two engine heads with different intake valve angles (11°and 26°) were tested in theflow bench by varying the evaluating position (1.75~6.0B) and valve lift (2~10 mm). Particle image velocimetry was used tomeasure the velocity field inside the engine cylinder. The swirl center position is found with a critical point theory and the intensityof turbulence is calculated from PIV velocity data. The results show that the center of swirl is located closer to thecenter of cylinder and turbulence intensity is lower, when the intake valve angle is the smaller. It is conventional to evaluatethe swirl ratio at 1.75B position in the steady flow bench of SI engine. At this position, however, the distance of swirl centerfrom the cylinder center scatters significantly for the variation of valve lift, and the turbulence intensity is much stronger regardlessof the valve angle. Thus, to estimate the flow at the end of compression stroke in a real engine from the data in thesteady flow experiments, the evaluation position should be moved further downstream more than 4.5B.
Abstract
In this study, the variations of swirl center according to evaluating position have been investigated in a steady flowbench of SI engine. For the experiments, two engine heads with different intake valve angles (11°and 26°) were tested in theflow bench by varying the evaluating position (1.75~6.0B) and valve lift (2~10 mm). Particle image velocimetry was used tomeasure the velocity field inside the engine cylinder. The swirl center position is found with a critical point theory and the intensityof turbulence is calculated from PIV velocity data. The results show that the center of swirl is located closer to thecenter of cylinder and turbulence intensity is lower, when the intake valve angle is the smaller. It is conventional to evaluatethe swirl ratio at 1.75B position in the steady flow bench of SI engine. At this position, however, the distance of swirl centerfrom the cylinder center scatters significantly for the variation of valve lift, and the turbulence intensity is much stronger regardlessof the valve angle. Thus, to estimate the flow at the end of compression stroke in a real engine from the data in thesteady flow experiments, the evaluation position should be moved further downstream more than 4.5B.
참고문헌 (15)
- A. A. Quader, "The axially-stratified-charge engine", Society of Automotive Engineers, (820131) (1982)
- 엄인용, "EFFECT OF FUEL STRATIFICATION ON INITIAL FLAME DEVELOPMENT: PART 3−HIGH SWIRL CONDITION", International Journal of Automotive Technology, 12(5), pp.653~660 (2011), 한국자동차공학회
- K. Horie, "The development of a high fuel economy and high performance four valve lean burn engine", Journal of Society of Automotive Engineers, (920455) (1992)
- T. Inoue, "Toyota lean combustion system - The third gen-eration system", Journal of Society of Automotive Engineers, (930873) (1993)
- 엄인용, "흡입 밸브 각도에 따른 압축 행정 중 실린더 내 유동 특성", 한국자동차공학회 논문집, 14(4), pp.77~83 (2006), 한국자동차공학회
- 엄인용, "나선형 포트를 적용한 광각엔진에서 실린더 내 압축 유동 특성", 대한기계학회논문집 B, 33(1), pp.9~16 (2009), 대한기계학회
- 엄인용, "흡입밸브 각이 실린더 내 와류 발생 특성에 미치는 영향(II)", 한국자동차공학회 논문집, 17(2), pp.42~48 (2009), 한국자동차공학회
- I. Y. Ohm, "Development of HMC axially stratified lean combustion engine", Society of Automotive Engineers Transactions, 103(3), pp.1298~1311 (1994)
- I. Y. Ohm, "Initial flame development under fuel stratified con-dition", Society of Automotive Engineers Transactions, 107(3), pp.1796~1807 (1999)
- I. Y. Ohm, "Mechanism of axial stratification and its effect in an SI engine", Society of Automotive Engineers Transactions, 109(4) (2001)
- I. Y. Ohm, "In-cylinder fuel behavior according to fuel injection timing and port character-istics in an SI engine: Part III-with high swirl", Transactions of Korean Society of Automotive Engineers, 9(3), pp.18~26 (2001)
- I. Y. Ohm, "Characteristics of Mixture Distribution and Flame Propagation in an SI Engine according to Intake Flow", 박사, pp.1997
- Superflow Corporation, "Superflow 600 Instructions", ~ (1988)
- J. Sung, "Three-dimensional phase-averaging of time-resolved PIV measurement data", Journal of Measurement Science and Technology, 12(6), pp.655~662 (2001)
- A. E. Perry, "A description of ed-dying motions and flow patterns using critical-point concepts", Journal of Annual Review of Fluid Mechanics, 19, pp.125~155 (1987)