并行建表化学加速算法研究及其在气相斜爆轰模拟中的应用

采用详细化学反应机理对气相斜爆轰问题开展数值计算时,由于组分之间的特征时间尺度相差很大,反应源项的直接积分(direct integration,DI)求解通常存在强烈的刚性及非线性现象,导致计算量很大.为了在不损失计算精度的基础上有效减少化学反应过程的计算时间,针对包含2H2+O2详细机理的二维斜爆轰并行计算,提出两...

Parallel Chemistry Acceleration Algorithms and Application in Numerical Simulations of Gaseous Oblique Detonation Wave

In the numerical simulations of oblique detonation wave with the detailed chemical reaction mechanism,the computation of chemical reactions costs a large amount of CPU time due to the stiffness and non-linearity.To decrease the computational costs for the chemistry computation,a series of parallel chemistry acceleration algorithms based on the reduced in situ adaptive tabulation(ISAT)method were proposed for simulations of transient compressible reacting flows.These algorithms were applied in two-dimensional 2H₂+O₂ gaseous oblique detonation computations to identify the computational performances of chemistry acceleration.Compared with the computational results by direct integration(DI),all the parallel chemistry acceleration algorithms can improve the computational efficiency of chemical reactions without the loss of computational accuracy.The maximum speedup ratio of 3.71 is obtained for the purely transposed processing(TP)algorithm.The analyses also indicate that the selection on the parallel strategies could influence the computational efficiency,which essentially is dominated by the scatter distribution rules of chemical thermodynamic states in the accessed region and the repeatable region.