旋转爆轰发动机燃烧室的燃烧与流动特性研究

Study on combustion and flow characteristics in a rotating detonation combustor

设计了一台爆轰环腔外径100mm、内径80mm、长117mm的不带有尾喷管的旋转爆轰发动机燃烧室,并进行了实验和数值模拟研究,来了解不同当量比下的燃烧和流动特性。在该燃烧室头部,空气通过60个直径2mm孔轴向喷射,氢气通过2mm宽环缝喷射。氢气和空气最大供给总压分别可达12和10.5MPa。实验发现,当量比大于2时,燃烧发生在燃烧室以外,为爆燃;当量比接近于1时,燃烧室内存在多个反向旋转爆轰波,爆轰波平均速度较低,不超过1000m/s;当量比小于0.58时,仅有一个爆轰波准稳态旋转。在当量比为0.55时,旋转爆轰波传播速度为1274m/s。在当量比为1时,进行了17s无热防护的旋转爆轰发动机实验,未发现燃烧室有明显烧蚀。数值模拟表明在流量为400g/s时,有3个爆轰波同向旋转,外壁面侧传播速度约为1998m/s。

A rotating detonation combustor with the outer diameter100 mm,the inner diameter 80 mm and the axial length 117 mm for the detonation channel was designed.There is no exhaust nozzle attached to the combustor.Numerical and experimental studies were carried out to study combustion and flow characteristics under different equivalence ratio conditions.The air flows into the combustor through 60 orifices each with 2mm in diameter,and the hydrogen gas flows into the combustor through an annular channel with 2mm in width.The maximum total pressures of hydrogen and air can be 12 and 10.5MPa,respectively.When the equivalence ratio is greater than 2,deflagration occurs outside the combustor.When the equivalence ratio is close to1,multiple counter-rotating detonation waves move in the combustor and the average detonation velocities are lower than 1000m/s.When the equivalence ratio is less than 0.58,only one detonation wave rotates.The detonation velocity is 1274m/s for the equivalence ratio 0.55.The rotating detonation engine without cooling ran for 17 seconds at the equivalence ratio 1and apparent erosion wasn＇t found.Three detonation waves are co-rotating with velocities 1998m/s near the outer wall for the mass flow rate 400g/s in the numerical study.