摘要
为了研究泄漏对微发动机工作过程产生的影响,对自由活塞单次冲击压缩着火过程进行了可视化试验,得到不同漏气工况下微发动机的着火特性.在此基础上,建立了耦合自由活塞运动与燃烧过程的多维计算模型,对微HCCI燃烧过程进行了数值模拟.结果表明:混合气泄漏对着火时刻影响不大,但对活塞运动特性影响很大,漏气使得微燃烧室内压力降低,活塞返回速度变小,微发动机动力性能降低;泄漏间隙和泄漏长度是影响混合气泄漏程度的2个主要因素,也影响微压缩燃烧过程,泄漏间隙越大,最大压力与活塞末速度越小,动力性能越差,而泄漏长度增加,最大压力有所提高,有助于动力性能的提高;在微发动研究与设计过程中,应重视气缸/活塞间的密封效果.
Abstract ： In order to investigate the effect of leakage on the working process of micro freepiston engine, the singleshot visual experiment of homogeneous charge compression ignition （HCCL） in micro freepis ton engine was carried out to obtain different ignition characteristics under different leakage conditions. The multidimensional model with chemical dynamic and piston dynamic was established to simulate the process of HCCI. The results show that mixed gas leakage has slight effect on ignition time, while the leakage has severe effect on piston movement characteristic. Due to leakage, the pressure in the micro combustion chamber and the piston speed in the expansion process decrease with decreased performance of micro engine. The leakage gap and length are the main effect factors on the extent of gas leakage and the micro HCCI combustion processes. The larger the leakage gap is, the smaller the maximum pressure and the piston final velocity are, and the power performance becomes worse. With the increasing of lea kage length, the maximum pressure increases to improve the power performance. During the research and design process of micro engine, attention should be paid to the sealing effect between cylinder and piston.
出处
《江苏大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第1期14-19,共6页
Journal of Jiangsu University：Natural Science Edition
基金
国家自然科学基金资助项目(51076060)
江苏省研究生科研创新计划项目(CXZZ12_0672)
关键词
微自由活塞发动机
泄漏
可视化试验
HCCI
自由活塞
数值模拟
micro free-piston engine
leakage
visual experiment
homogeneous charge compression ig-nition （HCCI）
free-piston
numerical simulation
