Study On Parameters Influencing Characteristics Of Intake And Exhale System Of Turbocharged Direct Injection Engine And Multi-objective Optimization

Since the 21 st century,the popularity of small passenger cars as a means of transportation for people to travel has been greatly improved with the improvement of China’s economic level.At the same time,the energy crisis and environmental problems are also increasingly obvious with the increase of motor vehicles,supercharged direct injection engine as the mainstream power of passenger vehicles.Due to its technical advantages over naturally aspirated engines,as well as its excellent power performance and fuel economy,as well as its obvious role in reducing pollutant emissions,reducing mass,and reducing space occupancy,the pressurized direct injection technology has been rapidly popularized.Therefore,it is of great significance to carry out related research on the turbocharged direct injection engine,improve its power performance and economy,and reduce emissions to reduce energy consumption and exhaust emissions.Based on a company’s 1.4 T turbocharged gasoline direct injection(GDI)engine as the research object,the details refer to the motor inlet and exhaust system with pressure straight eruption key performance parameters optimization,on the basis of related literature at home and abroad,first introduced the engine inlet and exhaust systems and computer numerical simulation technology of domestic and foreign research present situation,and then the engine cylinder model to establish the theoretical basis,into the exhaust pipe of the gas flow mathematical model as well as the solving method for engine simulation model are analyzed and expounded,finally using supercharging straight obtained bench test engine performance parameters and the calibrated simulation model,According to the general idea and analysis flow of the parameter influence characteristics and multi-objective optimization of the inlet and exhaust system of the turbocharged direct injection engine,a series of in-depth studies have been carried out on the parameter influence characteristics and multi-objective optimization of the engine inlet and exhaust system.The main research work of this paper includes:(1)For the research of 1.4 L turbocharged direct injection gasoline engine,based on the AVL-PUMA operating system,combining with the AVL 733 S oil consumption meter,AVL Indiset 630 combustion analyzer,AMA I60 gas analyzer equipment structures,engine test bench,the speed at 1000 RPM to 5200 RPM,working condition of external characteristic experiment measured pressure straight eruption motivation and outer characteristics such as power,torque and fuel consumption rate in the cases of performance data.(2)Based on one dimensional unsteady flow were measured physical theory deals with structural parameters of the engine,in simulation software GT-Power charging straight eruption motivation numerical simulation model,obtained the performance of the engine bench test data and simulation model in the same condition to calculate the performance of the data,this paper compares and analyzes the real data and simulation data error control within the scope of permissible error(5%)of the project.(3)Through the calculation of the simulation model,the influences of inlet and exhaust manifold diameter,inlet and exhaust manifold length,inlet and exhaust resonator volume and distribution phase shift on the performance of the turbocharged direct injection engine are analyzed.The influence of inlet and exhaust system parameters on the performance of the TDI engine is summarized,which provides a basis for the further optimization and improvement of the engine.The results show that the optimization of intake and exhaust manifold diameter and valve phase can greatly improve the engine dynamic performance at medium and high speeds,but not significantly improve the engine dynamic performance at low speeds.(4)Had a greater influence on the selection into the exhaust system of engine performance parameters as multi-objective optimization test factors,using experimental Design method(Design of Experiment,the DOE),with the length of the inlet manifold,intake manifold,exhaust manifold diameter,diameter exhaust phase,the air intake cavity volume and exhaust cavity volume as a response to the independent variable,power,torque and fuel consumption as a response to the second order response surface fitting,and the maximum power,maximum torque and the minimum fuel consumption rate as the optimization goal,with the help of multi-objective genetic algorithm(GA)optimization calculation.On the engine exhaust manifold diameter,length of inlet manifold,cavity volume and distribution phase after optimization,the supercharging straight eruption of motive power performance is greatly improved,the optimized engine 1500 r/min(lowest fuel consumption rate point)by 263.87 g/k Wh to reduce fuel consumption were 263.46 g/k Wh,specific fuel consumption by 0.15%,to 2000 r/min(maximum torque point)by 205.53 N.m torque up to 208.23 N.m,increased by 1.3% compared to the original machine,5000r/min(maximum power point)power increased from 91.49 k W to 96.41 k W,5.38% higher than the original machine.