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在激波管上进行了气相十氢萘/空气混合物的着火延迟测量,着火温度为950-1395 K,着火压力为1.82×105-16.56×105Pa,化学计量比分别为0.5、1.0和2.0.在侧窗处利用反射激波压力和CH*发射光来测出着火延迟时间.系统研究了着火温度、着火压力和化学计量比对十氢萘着火延迟时间的影响.实验结果显示着火温度和着火压力的升高均会缩短着火延迟时间.首次在相对高和低压的条件下观察到了化学计量比对十氢萘着火延迟的影响是完全相反的.当压力为15.15×105Pa时,富油混合物呈现出最短的着火延迟时间,而贫油混合物的着火延迟时间却是最长的.相反,当压力为2.02×105Pa时,富油混合物的着火延迟时间最长.着火延迟数据与已有的动力学机理的预测值进行对比,结果显示机理在所有的实验条件下均很好地预测了实验着火延时趋势.为了探明化学计量比对着火延迟时间影响的本质,对高、低压条件下的着火延时进行了敏感度分析.结果显示,压力为2.02×105Pa时,控制着火延迟的关键反应为H+O2=OH+O,而涉及十氢萘及其相应自由基的反应在15.15×105Pa时对着火延迟起主要作用.
Ignition delay measurements of gas phase decalin / air mixture were carried out on a shock tube at a firing temperature of 950-1395 K with a firing pressure of 1.82 × 10 5 to 16.56 × 10 5 Pa with stoichiometric ratios of 0.5, 1.0 and 2.0, respectively The ignition delay time was measured by using the reflected shock pressure and CH * emission at the side windows.The effects of ignition temperature, ignition pressure and stoichiometry on the ignition delay time of decalin were systematically studied.The experimental results showed that the ignition temperature and ignition pressure Increases the ignition delay time.For the first time at relatively high and low pressure conditions, it was observed that the stoichiometry had the opposite effect on the detonation delay of decalin.When the pressure was 15.15 × 10 5 Pa, the oil-rich mixture showed The shortest ignition delay time, while the lean mixture has the longest ignition delay.On the contrary, when the pressure is 2.02 × 105Pa, the ignition delay of oil-rich mixture is the longest.The ignition delay data and the existing kinetic mechanism The results show that the mechanism predicts the good fire delay trend under all the experimental conditions.In order to find out the essence of the impact of stoichiometry on the fire delay time, The sensitivity analysis of the ignition delay under high and low pressure conditions showed that the critical reaction to control the fire retardation was H + O2 = OH + O at pressure 2.02 × 105 Pa, but the decalin and its corresponding free The radical reaction played a major role in retarding the fire at 15.15 × 10 5 Pa.