自由活塞内燃发电机低速不稳定性影响因素分析
发布时间：2018-09-19 13:50
【摘要】：单缸低速试验表明,自由活塞内燃发电机低速模式缸内燃烧并不稳定,呈间隔循环着火。为探索其原因,构建了系统CFD(计算流体力学)模型,对比分析了自由活塞内燃发电机换气过程与传统二冲程内燃机换气过程之间的差异,通过计算解释了试验中着火不稳定的现象,并得到了换气过程中影响换气效果的关键因素是扫气箱容积变化率的结论。随后探寻改善自由活塞内燃发电机低速不稳定性的设计策略,在计算模型中进一步研究了动子(磁棒)直径、扫气箱容积、进气增压压力对换气过程的影响。研究发现:减小动子直径与缸径比、对进气增压能显著改善自由活塞内燃发电机的换气效果,而在保证提供充分混合气量基础上扫气箱容积的改变对换气效果影响不大。
[Abstract]:The single cylinder low speed test shows that the combustion in the low speed mode of the free piston internal combustion generator is unstable and the combustion is intermittent cyclic ignition. In order to explore the causes, a CFD (Computational fluid Dynamics) model is constructed, and the differences between the air exchange process of the free piston internal combustion generator and the traditional two-stroke internal combustion engine are compared and analyzed. The phenomenon of unstable ignition in the test is explained by calculation, and the conclusion is drawn that the key factor affecting the ventilation effect is the volume change rate of the scavenging box. Then the design strategy to improve the low speed instability of the free piston internal combustion generator is explored. In the calculation model, the effects of the diameter of the rotor (magnetic rod), the volume of the scavenging box and the inlet pressure on the air exchange process are further studied. It is found that reducing the ratio of the diameter of the mover to the diameter of the cylinder can significantly improve the air exchange efficiency of the free piston internal combustion generator, but the change of the volume of the scavenging box has little effect on the ventilation effect on the basis of ensuring the sufficient mixture volume.
【作者单位】： 北京理工大学机械与车辆学院;
【基金】：国家自然科学基金(51276019)
【分类号】：TM314;TK441
，
本文编号：2250311
[Abstract]:The single cylinder low speed test shows that the combustion in the low speed mode of the free piston internal combustion generator is unstable and the combustion is intermittent cyclic ignition. In order to explore the causes, a CFD (Computational fluid Dynamics) model is constructed, and the differences between the air exchange process of the free piston internal combustion generator and the traditional two-stroke internal combustion engine are compared and analyzed. The phenomenon of unstable ignition in the test is explained by calculation, and the conclusion is drawn that the key factor affecting the ventilation effect is the volume change rate of the scavenging box. Then the design strategy to improve the low speed instability of the free piston internal combustion generator is explored. In the calculation model, the effects of the diameter of the rotor (magnetic rod), the volume of the scavenging box and the inlet pressure on the air exchange process are further studied. It is found that reducing the ratio of the diameter of the mover to the diameter of the cylinder can significantly improve the air exchange efficiency of the free piston internal combustion generator, but the change of the volume of the scavenging box has little effect on the ventilation effect on the basis of ensuring the sufficient mixture volume.
【作者单位】： 北京理工大学机械与车辆学院;
【基金】：国家自然科学基金(51276019)
【分类号】：TM314;TK441
，
本文编号：2250311
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