The objective of the present analysis is to investigate the effect of gaseous hydrocarbon fuels, such as Octane C8H18, Hexane C6H14, and Pentane C5H12 on the cyclic combustion process in an obstructed channel of the pulse detonation engine. Three-dimensional reactive Navier-Stokes equations are used to simulate the combustion mechanism of stoichiometric hydrocarbon fuels along with a one-step reaction model. The fuel is injected at atmospheric pressure and temperature and is ignited with pre-heated air. The investigation shows that initially a high-temperature combustion wave propagates with the local speed of sound; it creates turbulence after colliding with obstacles, resulting in an increase to supersonic flame speeds. Therefore, different values of the combustion flame propagation speed, combustion efficiency and impulse per unit area are obtained for these fuels. The detonation speed in the hexane-air mixture is about 5.8% lower than the detonation speed predicted by the NASA CEA400 code. However, it is observed that the octane fuel reduces the deflagration-to-detonation transition run-up distance as compared to other fuels.

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燃料-空气混合物的各种成分对脉冲爆震发动机性能的影响

本分析的目的是研究气态碳氢燃料，如辛烷 C8H18、己烷 C6H14 和戊烷 C5H12 对脉冲爆震发动机阻塞通道中循环燃烧过程的影响。三维反应纳维-斯托克斯方程用于模拟化学计量烃燃料的燃烧机理以及一步反应模型。燃料在大气压力和温度下喷射，并用预热空气点燃。调查表明，最初高温燃烧波以局部声​​速传播；它在与障碍物碰撞后产生湍流，导致超音速火焰速度增加。因此，不同值的燃烧火焰传播速度，获得这些燃料的燃烧效率和单位面积的冲量。己烷-空气混合物中的爆炸速度比 NASA CEA400 代码预测的爆炸速度低约 5.8%。然而，据观察，与其他燃料相比，辛烷值燃料减少了爆燃到爆轰的过渡加速距离。