computational fluid dynamics analysis of the scavenging process in the man b w - 副本推荐.pdf

Journal of Ship Research, Vol. 56, No. 3, September 2012, pp. 154–161 /10.5957/JOSR.56.3.120001 Computational Fluid Dynamics Analysis of the Scavenging Process in the MAN BW 7S50MC Two-Stroke Marine Diesel Engine ´ ´ Marıa Isabel Lamas and Carlos Gervasio Rodrıguez Vidal ´ ~ ~ Escola Universitaria Politecnica, Universidade da Coruna, Serantes, A Coruna, Galicia, Spain This paper focuses on a computational fluid dynamics (CFD) analysis to simulate the scavenging process in the MAN BW 7S50MC. This is a two-stroke diesel engine with uniflow scavenging. In recent years, low-speed, MC type two-stroke engines have become very popular in a huge number of different ships. Using the commercial soft- ware ANSYS Fluent, the pressure, velocity, and mass fraction fields were obtained, as well as the scavenging efficiency. As expected, the results show a swirling movement around the cylinder axis. To validate the numerical model, the in-cylinder pressure was successfully compared with experimental measurements, indicating that the proposed CFD approach can simulate the compression/expansion process with a good degree of accuracy. These results provide interesting information to improve two-stroke engines because the scavenging process plays a crucial role in pollution levels, performance, and efficiency. Accordingly, the aim of future work is to use this numerical model to improve the design of current large and medium marine engines. Keywords: two-stroke engine; computational fluid dynamics (CFD); scavenging