对数值模拟气相爆轰中二阶段化学反应模型再研究

Re-study on the two-step chemical reaction model in numerical simulation of gaseous detonation

采用改进的高精度时-空守恒元解元算法(the space-time conservation element and solution element meth-od,CE/SE method)和考虑组分的二阶段化学反应模型(Sichel的二步模型)对气相爆轰问题的数值模拟进行了分析。分析发现采用Sichel的二步模型得到的数值结果虽然比早期二阶段化学反应模型(旧二步模型)更接近实验值,但是仍然不能得到爆轰过程准确气体动力学参数。为此通过修改组分的质量分数分布形式对Sichel的二步模型进行了改造,然后采用新的二步模型对平面爆轰波进行了数值模拟。数值结果表明采用新的二步模型计算得到气体动力学参数更接近于实验值和基元反应模型的计算值,在计算精度上有较大提高。

Numerical simulations of the gaseous detonations are performed by using the extended CE/SE method （the space-time Conservation Element and Solution Element method） with high-order accuracy and the two-step chemical reaction model with species （Sichel＇s two-step chemical reaction model）. The analysis results show that Sichel＇s two-step chemical reaction model also can＇t obtain the exact gasdynamics parameters, thought it is more accurate than the original two-step chemical reaction model. The Sichel＇s two-step chemical reaction model is improved by modifying the distribution of components＇ mass fractions. A planar detonation problem is simulated by the new two-step chemical reaction model. Gasdynamics parameters obtained using the new two-step chemical reaction model agree well with the experimental results and the numerical results of the detailed chemical reaction model. The computational accuracy using the new two-step chemical reaction model is evidently improved.