عنوان مقاله [English]
نویسندگان [English]چکیده [English]
This research uses computational modeling to explore another method to increase diesel engine performance while maintaining low pollutant emission levels. Previous studies have shown that injection-rate profiles and injector configurations play important roles on the performance and emissions of particulate and NOx in DI diesel engines. Since the most important engine design parameters, including filling efficiency, flame stability, performance and pollutant formation depend on the local flow field in inlet port and then in cylinder, the ability to accurately predict these more details is a key requirement for successful application of computational fluid dynamics techniques to design and optimization engines. In this work which is done at Motorsazan.Co in order to optimize inlet port shape, a procedure is outlined for producing a computational mesh for intake port and in-cylinder geometry on 135TI diesel engine at various intake port shapes. After modeling the combustion chamber with inlet port, AVL FIRE software has been employed for grid generation and numerical simulation in an open cycle mode. The numerical results are validated by corresponding experimental data for base line engine. Concerning the design limitations, two new helical ports are introduced and simulated using the same solver, boundary and initial condi�tions. Final performance and pollutant emission results, obtained from new models are compared with those of the base model and the model with the best results is introduced as the optimum among all. This work demonstrates that multidimensional modeling at an open cycle can now be used to gain insight into the combustion process and provide direction to explore new engine concepts.