硝酸丙酯冲击点火的光谱研究

Spectral Studies on Shock Ignition of Propyl-nitrate

利用从头算起法计算了硝酸丙酯分子结构,计算表明:NO2基最容易脱落。实验上利用多种光谱技术确定硝酸丙酯冲击点火延迟时间的方法是:先用谱仪确定硝酸丙酯冲击点火最早出现的中间产物,对于硝酸丙酯NO2辐射总是先出现;把单色谱仪调至NO2(463nm)波长处,并利用压力传感器测得冲击波到达样品的时间便可确定硝酸丙酯冲击点火延迟时间。这种方法比国内外常用光电二极管(峰值波长约在800nm)的方法更接近实际值。硝酸丙酯受冲击后,反应中间产物出现的时间不同,辐射强度也不同。在冲击波作用下出现的基团为NO2、O、C2、CH、CO、CO2、H2O等,而NO2基总是首先出现。采用理论和实验相结合的方法确定冲击点火延迟时间可明显减少实验量。

A molecular structure of propyl-nitrate is calculated by using ab initio calculation method. The calculation results indicate that NO2 radical is fallen away more easily. The delay time of shock ignition is determined by using the method, i.e. intermediate product of the most early emergence for the loaded propyl-nitrate is determined at first with spectrometer, the emergence of intermediate product of NO2 for propyl-nitrate after shock ignition is always the most early. The monochrometer is adjusted to 463 nm wave length of NO2 , and the time of arriving for shock wave is measured with gauge. The delay time of shock ignition for propyl-nitrate is determined. The delay time determined by the method is closer than that of by using photo-electrlc diode whose peak wave length is about 800 nm. The measurement results show that the emergence of intermediate product of O for propyl-nitrate after shock ignition is different, and radiation intensity for the radicals is also different. The emergence times for O, NO2 , CO, C2 , CH, CO2 , H2O radicals is obtained after the shock wave enters into the propyl-nitrate. The emergence time of NO2 radical is the most early. The method combined the theory with the experiment may obviously decrease tests to determine shock ignition time.