受侧向膨胀弱约束边界影响的爆轰波传播特性数值研究OA北大核心CSTPCD

To investigate the propagation characteristics of detonation waves influenced by lateral expansion with weakly constrained boundaries in a narrow straight channel,a two-dimensional numerical simulation was conducted using H2/O2/Ar mixture as the fuel and a detailed chemical reaction mechanism consisting of 48 steps.The study examined the effects of type of weakly constrained gas,temperature,and height of combustible premixed gas on the propagation speed and wave structure of the detonation wave.It is found that using argon or products of combustion as weakly constrained gases has no significant impact on the lateral expansion extent and wave structure of the detonation wave.When the temperature of the weakly constrained gas is 1 000 K,1 500 K,and 2 000 K,the shock wave propagating within the products of combustion exceeds the detonation wave speed,resulting in the generation of an induced shock wave pointing towards the detonation wave.This induced shock wave leads to an increase in the velocity of the detonation wave.Increasing the temperature of the weakly constrained gas from 300 K to 500 K has no effect on the propagation characteristics of the detonation wave.Higher heights of combustible premixed gas results in less loss of velocity for the detonation wave,and there exists a minimum combustible premixed gas height that prevents the detonation wave from extinguishing.When the temperature of the weakly constrained gas is 300 K,the dimensionless critical propagation size of the detonation wave h/λ＞0.13.The findings of this study are of significant importance for understanding the mechanisms of lateral expansion losses in detonation waves.