Multi-Dimensional Simulation Of Intake Flow And In-Cylinder Combustion In A Highly Intensified Diesel Engine

Intake process of internal combustion engines has a decisive impact on the performance of internal combustion engines.It is very crucial for diesel engine to get good performance by getting adequate air and organizing intake flow well.Therefore, research into the gas flow to improve diesel engine performance has a positive practical significance.In this thesis, profited from the CFD software FIRE, a multi-dimensional simulation of intake-compression-combustion process on a highly intensified diesel engine has been done for researching the in-cylinder flow structure.Then, the research of grid dependence has been done for the research of the engine and a conculation model of the highly intensified diesel engine has been set up to adjust the EBU multi-dimensional combustion model parameter A and WAVE droplet breakup model parameter C2 until the performance of the highly intensified diesel engine match with the experiment date of combustion pressure in the cylinder and heat release profile. Then, an analysis of in-cylinder flow structure was done.And then, the effect of swirl rate, nozzle diameter, spray timing, spray angle and Combustion chamber shape of the engine are studied based on single parameter rotatory method.At last, the effects of five combustion system parameters and the interaction effect of four pairs of different combustion system parameters to the dynamic performance of the highly intensified diesel engine are investigated and analyzed based on the Orthogonal Experiment Method, different combustion system parameters are optimized based on the Orthogonal Experiment Method ,and optimized results are obtained.