煤油简化动力学和ISAT在超燃计算中的应用

利用基于"准稳态"方法建立的模型简化软件包SPARCK,从建立的详细模型出发得到了一个包含22组分18步总包反应的煤油简化动力学模型.简化模型计算得到的点火延迟时间与文献计算结果和实验结果相一致,验证了模型的有效性.采用简化模型和当地自适应建表(ISAT)方法,对超燃冲压发动机进行了二维并行数值模拟,计算得到的壁面压力分布与试验结果吻合较好,表明简化模型能够很好地用来模拟煤油燃料超燃发动机内部的复杂燃烧过程.在并行计算环境下,和直接积分方法相比,该方法将化学反应项的计算速度提高了3.73倍,大大提高了计算效率.

IMPLEMENTATION OF REDUCED CHEMICAL KINETICS FOR KEROSENE COMBUSTION AND IN SITU ADAPTIVE TABULATION IN PARALLEL COMPUTATIONS OF SCRAMJET

A detailed chemical kinetics model including 109 species and 946 elementary reactions for kerosene combustion was obtained. Then, using the software SPARCK (Software PAckage for Reduction of Chemical Kinetics) which is based on quasi-stationary state approximation and specifically developed for chemical reaction kinetics reduction, a reduced model with 22 species and 18 global reactions was achieved. The calculated ignition delay with this reduced model gives a good agreement with reference and experimental results to verify the reliability of the model. The 2-D parallel numerical simulation of scramjet was performed using in situ adaptive tabulation (ISAT) and the reduced model. The calculated results show that the distribution of wall pressure agrees well with the experimental measurements, and the reduced model can simulate well the complex combustion phenomena in a kerosene-fueled scramjet. Compared with that of the direct integration method, the results show that ISAT method can reduce the CPU time up to 3.73 times under the present parallel environment and the computational efficiency can be dramatically enhanced.