论文部分内容阅读
为了更深入地了解和掌握多凹腔双模态冲压发动机的燃料喷注方案对燃烧室流场结构和工作性能的影响,开展了模拟飞行马赫数4.5~5.0及总温1048~1231K范围内变化的多凹腔双模态冲压发动机地面直连试验。通过试验,得到了不同喷注当量比、喷注位置或喷注级数条件下稳定的壁面压力分布和出口总压数据,并采用一维冲量分析程序对试验数据进行了详细处理和分析。结果表明:提高喷注当量比能有效地提高发动机的推力,但燃烧效率和发动机比冲会降低;将燃料喷注位置提前能使发动机的燃烧效率和推力分别提高5.6%和4.4%;燃料的分配方案对燃烧室的流场结构有明显影响,热力喉道的位置随燃料更集中地在下凹腔喷注而更靠下游,且要形成该热力喉道则需加入更多热量;采用上下游的两级喷注能形成较宽范围的亚声速区,有利于燃料的燃烧释热,可使燃烧室效率和发动机推力分别提高10.4%和10.8%。
In order to understand and grasp the influence of the fuel injection scheme of the multi-cavity bimodal ramjet engine on the flow field structure and working performance of the combustor, the changes of Mach number 4.5 ~ 5.0 and total temperature 1048 ~ 1231K Multi-cavity dual-mode ramjet ground direct connection test. Through the experiment, the steady wall pressure distribution and total outlet pressure data were obtained under different injection equivalence ratio, injection position or injection series, and the experimental data were processed and analyzed in detail by one-dimensional impulse analysis program. The results show that raising the injection equivalence ratio can effectively improve the thrust of the engine, but the combustion efficiency and the engine specific impulse decrease; the advance of the fuel injection position can improve the combustion efficiency and thrust of the engine by 5.6% and 4.4% respectively; The distribution scheme has a significant effect on the flow field structure of the combustion chamber, the location of the thermal throat is more downstream with the fuel injected in the lower cavity, and more heat is required to form the thermal throat; upstream and downstream The two-stage injection can form a wide range of sub-sonic zone, which is conducive to fuel combustion and heat release, which can improve the combustion chamber efficiency and engine thrust by 10.4% and 10.8% respectively.