Study On Numerical Simulation Of Diesel Engine Intake Process

For diesel engine, to improve the formation and combustion of the mixture and to improve the engine's power, fuel economy and emissions targets, in addition to selecting the appropriate inlet swirl ratio for the best, it's necessary to increase the gas charge into the diesel engine cylinder, while the structural parameters of the intake system has a relationship with the intake gas charge; so it's of great significance for improving engine performance that we do some research on the influence rules of the structural parameters of the intake system on the gas charge.Rationally design the intake and exhaust system is one of the effective measures to improve the engine volumetric efficiency. The gas pressure fluctuations in the intake pipe affect the gas charge not only in the intake valve opening time but also in the intake valve closing time of the next engine cycle. The degree of influence of pressure fluctuations on the gas charge has a relationship with the intake pipe length, diameter, engine speed and other factors.With the development of computer technology, people prefer to use numerical simulation combined with a few experiments to develop the intake system. Through the proper use of simulation, we can easily predict and compare a variety of projects, analyze various inflation factors on engine performance, in order to determine the direction of its improvement, and in the end through a small number of test verification, we can achieve the purpose of improving diesel engine performance.This paper studies the influence of intake system of a single cylinder diesel engine on intake manifold pressure fluctuations, intake gas charge and pumping loss. Through the combination of experiment and simulation, we confirm the rational design parameters of intake system; Through the effective use of intake resonance, we improve the intake system pressure fluctuations and improve the engine volumetric efficiency and lower air intake losses, thereby improving engine performance. Firstly. I have read a lot of literature of related topics, based on a systematic summary of the engine intake resonance research, studied the simulation calculations of the physical and mathematical models; Secondly, I establish a single-cylinder diesel engine simulation model through the use of the engine one-dimensional fluid calculation software AVL Boost, and validate the reliability of the model through the calculation result and the experimental data; Then, using the established simulation model of diesel engine working process, all parts of the engine intake system are optimized, and the best intake system parameters are given; Finally, in order to take full advantage of the dynamic effect of the engine intake system, I design a new type of air filter, describe the working principle and present the overall structure.