冲压发动机燃烧引起激波运动过程一维分析

分析了冲压发动机喷油燃烧引起内流道内正激波运动的机理,采用一维激波捕捉方法,建立了燃油喷入对正激波运动位置影响的一维仿真模型。通过仿真发现:喷入燃油并逐步增大燃油-空气当量比时,正激波逐步向上游运动;燃油-空气当量比越大,正激波越接近进气道喉道;当燃油-空气当量比增大到一定程度时,正激波距离进气道喉道最近,但并未越过喉道;进一步增大燃油-空气当量比,正激波开始向下游回退进一步分析发现:冲压发动机流道及燃烧组织匹配设计直接影响到正激波在流道内的运动位置,需要在设计中格外重视。燃油-空气当量比与激波位置的关系分析可为冲压发动机设计提供一定的理论参考。

One-dimensional analysis of shock movement caused by combustion in ramjet

The mechanism of normal shock movement due to fuel injecting combustion in ramjet burner is analyzed in this paper. By one-dimensional shock wave automatic capturing method, a one-dimensional simulation model was built to analyze the impact of the fuel-air equivalence ratio on the location of the normal shock wave motion in ramjet duct. It is drawn by the simulation results that the normal shock moves upstream at the reversed flow direction in the case of an increase of the fuel-air equivalence ratio; the higher the fuel-air equivalence ratio is, the nearer the normal shock wave approaches to the inlet throat; the distance between the normal shock wave and the inlet throat is shortest when the fuel-air equivalence ratio reaches to a certain extent, （however, the normal shock wave never exceeds the inlet throat）; the normal shock wave moves back to the downstream when the fuel-air equivalence ratio is further increased. It is concluded by further analysis that additional attention must be paid to the flow channel and combustion in ramjet design to determine the location of the normal shock wave in duct. The results and conclusions in the paper can be referenced in ramjet design.