脉冲爆轰发动机热射流起爆机理数值分析

应用频散可控耗散差分格式,求解具有化学反应项的Euler方程,探讨了热射流起爆可燃混合气缩短DDT过程的物理机制.数值研究模拟了不同条件下的起爆过程,从氢氧链式反应出发详细分析了氢氧爆轰直接起爆的SWACER(能量释放而形成激波或压缩波的相干放大)机制的建立条件,讨论了热射流起爆存在超临界、临界和亚临界三种直接起爆机制.

Numerical Analyses of Direct Detonation Initiation in PDEs with a Pre-combustion Jet

Direct onset detonation initiated by high temperature jets from a pre-combustion tube is investigated numerically. A dispersioncontrolled dissipative scheme is adopted to solve Euler equations with axis-symmetric flows implemented with detailed chemical reaction kinetics of the hydrogen-oxygen mixture. For validation and verification purpose, computational results are compared with experimental results. Three regimes of direct detonation initiation, referred to as supercritical, critical and subcritical ones, are demonstrated with numerical analyses from a viewpoint of chain reactions. The regimes are affected by the PDEs geometric configuration. It is recognized that the SWACER mechanism plays an important role in the state transit of chemically reacting flows in which the gradient of chemical radicals presents properly.