A review on the influence of in-cylinder turbulence type on combustion characteristics of high power-density diesel engine

With the continuous improvement of performance requirements, direct injection diesel engines have gradually developed towards more small, lightweight, and high power, named as high power-density. It needs more injected fuel can be mixed and burn at the same duration time to guarantee the thermal-power conversion effects. It is required that the combustion system has a fast mixing speed of fuel and gas, and a fast combustion speed. Organizing appropriate cylinder turbulence is an effective means of optimizing combustion to reach requirements. The current work is aim to investigates and summarizes the influence of different types of in cylinder turbulence coursed by intake, spray, and combustion chamber configuration on the performance of a highly intensified diesel engine from the three causes of turbulence. The comparative study found that the adoption of a separate combustion chamber, the increase of intake swirl and number of nozzles can have positive effect on the optimization of the combustion process of a highly intensified diesel engine, but for different combustion chamber types, the influence of intake swirl and spray parameters was different. The separated combustion chamber is more sensitive to spray parameters than the combustion chamber without wall guide design. Compared with the transverse separated combustion chamber, the longitudinal separated combustion chamber is more suitable for large intake swirl ratio. For a specific combustion chamber structure, both intake swirl and spray parameters have optimal values.