电 热 塞 助 燃 对 天 然 气 射 流 点 火 特 性 的 影 响

In order to address the prolonged ignition delay of natural gas,a numerical simulation study on the ignition characteristics of natural gas assisted by glow plug(GP)was carried out. Results indicate that the GP effectively facilitates natural gas ignition,with the flame rapidly propagating from the circular opening and the bottom of the GP shield into the combustion chamber. Notably,the diamond multi-opening shield enhances flame propagation more effectively,and the ignition delay difference(IDD) is the smallest. The square multi-opening shield design prevents the natural gas jet from directly impinging on and cooling the GP surface,ensuring that the GP remains at an optimal temperature for ignition and reducing the ignition delay by temperature(IDT),compared to a single-opening shield. Additionally,elevated temperatures enhance natural gas ignition. When the GP temperature exceeds 1 400 K,the shield opening design becomes unnecessary. In these conditions,although a single-opening shield can achieve similar ignition performance with ignition time of about 0. 3 ms,it may adversely affect the GP’s lifespan.