Experiment And Numerical Simulation Research Of Spray And Combustion Process In 26/32 Series Diesel Engine From CNPC Jichai

As the key point of diesel engine working process,the spray and combustion process of diesel engine became one main emphasis of current internal combustion engine research.The application of numerical simulation technology makes it more efficient and convenient to study the spray and combustion process of diesel engine.Based on the experimental data of 12V26/32 diesel engine from CNPC Jichai Power Equipment Company,the three-dimensionally and numerically simulation of the process of in-cylinder spray and combustion of 26/32 series diesel engine is made by using CFD software FLUENT.Some factors which influence the characteristics of spray and combustion and the generation of emissions are analyzed by observing the fuel distribution and the formation process of combustion products of the process of diesel engine spray and combustion.The research in this dissertation shows that the formative speed of nitrogen oxide increases with the rise of temperature,and the content constantly increases and becomes stable when up to certain value,but the content of soot followes the trend that rose first and then fell.The change of the cone angle affects the fuel's blending in cylinder and the oil droplets' collision.The height of the nozzle hole affects the blending in cylinder.Three combustion chamber of different depths were designed on the condition of the original compression ratio and cavity diameter remains unchanged.The result shows that with the increase of the depth of combustion chamber,the content of nitrogen oxides in the emissions increases while the content of soot decreases,which provides theoretical support for the design of combustion chamber.