Abstract:

In order to promote efficient application of the pre-combustion chamber ignition system and strengthen understanding of the hot jet itself， the influence of the key structural parameters on the formation of the mixture and the development characteristics of the hot jet in the pre-combustion chamber is studied through the Converge software simulation. The research results show that with the increase of surface-to-volume ratio and cross-section ratio， the penetration distance and distribution area of the jet flame both show a trend of increasing first and then decreasing. When the surface-to-volume ratio of the pre-combustion chamber is 0.02-0.036 cm^-1， a relatively large penetration distance and distribution area can be obtained； at the same time， a smaller surface-to-volume ratio is more conducive to the development of the heat jet in its axial direction， and the pre-combustion chamber with a larger surface-to-volume ratio has a larger radial diffusion range of the heat jet. The cross-section ratio of 0.15 and 0.20 can obtain relatively larger penetration distance and distribution area. When the cross-section is larger， the quality of the mixture formed in the pre-combustion chamber deteriorates and the combustion pressure decreases； when the cross-section gets smaller， the combustion pressure also decreases. When the upper structure of the pre-combustion chamber adopts the circular truncated cone structure， relatively better combustion pressure as well as penetration distance and distribution area of the jet flame can be obtained， and the jet formation and development performance are poorer when the stepped structure is adopted.

Key words: pre-combustion chamber structural parameters, hot jet characteristics, numerical simulation