T-GDI 엔진의 속도 및 하중이 블로우바이 가스의 오일입자 크기와 오일분리기 성능에 미치는 영향에 대한 실험 및 수치적 연구

• Published in: 한국분무공학회지 Vol. 25; no. 4; pp. 162 - 169
• Main Authors: 정수진, Soo-jin Jeong, 오광호, Kwangho Oh
• Format: Journal Article
• Language: Korean
• Published: 한국분무공학회 31.12.2020
• Subjects: Blow-by gas; CFD; Oil-mist separator; Particle size analyzer; Separation efficiency; T-GDI Engine; Turbocharged Gasoline Direct Injection Engine; 과급형 가솔린 직분식 엔진; 기계공학; 분리효율; 블로우바이가스; 오일 분리기; 입자분석기; 전산유체역학
• ISSN: 1226-2277; 2288-9051

The worldwide focus on reducing the emissions, fuel and lubricant consumption in T-GDI engines is leading engineers to consider the crankcase ventilation and oil mist separation system as an important means of control. In today’s passenger cars, the oil mist separation systems mainly use the inertia effect (e.g. labyrinth, cyclone etc.). Therefore, this study has investigated high efficiency cylinder head-integrated oil-mist separator by using a compact multi-impactor type oil mist separator system to ensure adequate oil mist separation performance. For this purpose, engine dynamometer testing with oil particle efficiency measurement equipment and 3D two-phase flow simulation have been performed for various engine operating conditions. Tests with an actual engine on a dynamometer showed oil aerosol particle size distributions varied depending on operating conditions. For instance, high rpm and load increases bot only blow-by gases but the amount of small size oil droplets. Submicron-sized particles (less than 0.5 μm) were also observed. It is also found that the impactor type separator is able to separate nearly no droplets of diameter lower than 3 μm. CFD results showed that the complex aerodynamics processes that lead to strong impingement and break-up can strip out large droplets and generate more small size droplets.