基于LIBS的定容燃烧弹内乙醇直喷局部当量比测定

Based on laser-induced breakdown spectrum (LIBS), the local equivalence ratio of ethanol injection at the center of a constant volume bomb was studied under different injection pressures, injection pulse widths and premixed-injection ratios. The experimental results show that when the global equivalence ratio remained the same, the local equivalence ratio at the center of the bomb increased first and then decreased with time under different injection pressures. The higher the injection pressure, the greater the increase in the local equivalence ratio, and the faster the maximum peak value was reached. Different injection time had little influence on the change of local equivalence ratio. The larger the premix ratio, the longer the time required to reach the equilibrium, while the change of local equivalence ratio was rather gentle.