Unsteady transverse injection of kerosene into a supersonic flow

A shadowgraph and a new fuel injection system were used to study kerosene transversely injected into a supersonic flow. High pressure and velocity of injection can be attained. The pressure time histories were detected in oil-line and the shadowgraphs of the flow field were obtained at different time-delays. The inflow stagnation pressure was varied to change the local flow speed in test section. The results indicate that kerosene jet exhibits deep penetration and four regimes appear clearly during the fuel jet atomization in a high-speed flow. The jet disintegration is caused by surface waves propagating along the jet surface, and the breakup point is located at the wave trough. The surface waves are dominantly generated by aerodynamic force. The jet shock is close to windward surface of the jet. The shock reflects on and transmits in duct boundary layers. In the case of unsteady injection, the shock structure is very complicated and different from that of hydrogen injection. The results of kerosene inj     

柴油在亚、超声速气流中横向喷射实验研究

改造普通油嘴,采用单次高压燃油喷射系统和阴影照相,首次研究了柴油射流柱在亚、超声速气流中横向非定常喷射问题。忽略破碎和雾化过程,用双流体模型和高精度格式,对该问题进行了初步的数值模拟。结果表明：沿射流柱表面传播的表面波是引起射流柱破碎的主要因素,破碎点位于表面波的波谷。高速气流中射流柱的雾化过程可分为射流柱区、大液块的首次破碎区、小液块的二次破碎区和液滴区。射流激波贴近射流柱迎风面,为三维凸形结构,在通道内反射,形成非定常的复杂波系结构。射流、来流动压比是影响柴油穿透深度的关键参数。计算得到的液相等密度线分布与实验结果在定性上一致。