预燃火焰引燃高压甲烷射流的数值模拟  

Numerical Simulation of High-Pressure Methane Jet Ignited by Pre-Combustion Flame

作　　者：仇滔[1] 邓玉婉 雷艳[1] 马雪健 石磊 王晓艳 Qiu Tao;Deng Yuwan;Lei Yan;Ma Xuejian;Shi Lei;Wang Xiaoyan(Department of Environment and Life Science,Beijing University of Technology,Beijing 100124,China;State Key Laboratory of Internal Combustion Engine Reliability,Weifang 261061,China)

机构地区：[1]北京工业大学环境与生命学部,北京100124 [2]内燃机可靠性国家重点实验室,山东潍坊261061

出　　处：《内燃机学报》2022年第6期513-518,共6页Transactions of Csice

基　　金：国家自然科学基金资助项目(91641106);内燃机可靠性国家重点实验室开放基金资助项目(skler-201913)。

摘　　要：天然气缸内高压直喷(HPDI)发动机的燃烧是柴油在缸内着火形成预燃火焰、天然气高压射流进入气缸并被该火焰继续引燃的过程,研究天然气射流与预燃火焰之间的关系对天然气HPDI发动机十分重要.基于Fluent软件,对预燃火焰引燃高压甲烷射流过程进行模拟,结果表明:沿喷射方向,射流先从未燃区进入预燃火焰已燃区,射流气体未达到着火温度未被引燃,之后,射流从预燃火焰已燃区进入未燃区,成功被引燃;分析不同位置火焰温度随时间的变化,提出在轴线上根据温度和反应速率两个参数的变化确定引燃区和未引燃区分界点的方法;射流的扰动传质与火焰强度的协同作用使射流被引燃,火焰由预燃层流燃烧变为引燃湍流燃烧继续传播发展.The combustion process of a high-pressure direct injection(HPDI) natural gas engine has such a characteristic that the diesel fuel is ignited first to form a pre-combustion flame,then the high-pressure natural gas jet enters the cylinder and is ignited by the flame. It is very important to study the relationship between the natural gas jet and the pre-combustion flame for the HPDI natural gas engine. Based on the Fluent software,the process of highpressure methane jet ignited by pre-combustion flame was simulated. It is found that,the jet,which enters the burned zone from the unburned zone,can not be ignited until the ignition temperature is reached. The jet,which enters the unburned zone from the burned zone,can be ignited. Based on the analysis of the variation law of flame temperature parameters and reaction rate with time at different positions,the method of defining the demarcation point of ignition zone and non-ignition zone on the axis was presented. Mass transfer by jet disturbance and flame intensity leads to the ignition of the jet,and the flame continues to propagate and develop from the laminar combustion of pre-combustion to the turbulent combustion of ignition.

关 键 词：天然气发动机 直喷 高压射流 预燃火焰 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]