基于激波管正庚烷点火延时的实验研究

本文采用激波管研究了正庚烷在不同条件下的点火延时特性,首先考察了当量比为0.5,0.7,1.0时正庚烷/合成空气混合气的点火延时特性；其次在当量比不变和变化的条件下,研究了合成空气中CO2的比例以及压力对点火延时的影响.实验结果表明:在温度高于1 200K时,正庚烷点火延时随当量比增加而增大；改变合成空气中O2与CO2的比例时,点火延时随CO2的比例增加而增大；维持当量比不变,当激波管高、低压段初始压力相同时,点火延时随CO2的比例增加而增大；同时还发现当量比对点火延时的影响随着CO2比例的增加而减小.

Experimental Investigation of Ignition Delay Time of n-Heptane in Shock Tube

In this paper,an experimental study was carried out on ignition delay time of n-heptane at different conditions in a shock tube.First,ignition delay time of n-heptane in synthetic air with different equivalence ratios(Φ=0.5,0.7,1.0) were studied.Second,the influences of CO2 ratio and pressure on ignition delay time were studied when equivalence ratio changed and unchanged.Experimental results show that: the increase of equivalence ratio makes the ignition delay time longer when the temperature is higher than 1 200 K and increase of CO2 ratio in synthetic air makes the ignition delay time longer.Under the same equivalence ratio and the same original pressures in driver and driven sections of the shock tube,when an increasingly amount of CO2 was added into the fuel/synthetic air mixture,the ignition delay time became longer.Furthermore,the influences of the equivalence ratio on ignition delay time became smaller when the ratio of CO2 became lager.