Experimental investigation on a rotating detonation cycle with burned gas backflow
Experimental investigation on a rotating detonation cycle with burned gas backflow
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DOI：
10.1016/j.combustflame.2020.10.048
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发表时间：
2021-03
影响因子：
4.4
通讯作者：
K. Matsuoka;Masaya Tanaka;T. Noda;A. Kawasaki;J. Kasahara
中科院分区：
文献类型：
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作者：
K. Matsuoka;Masaya Tanaka;T. Noda;A. Kawasaki;J. Kasahara
为了分析燃烧气体回流的旋转爆轰循环(RDC)，用乙烯和氧气气体同时进行了自发光显示、压力和推力测量。三种不同的几何阻塞率(燃烧室底壁表面面积与燃烧室横截面积之比)分别为89.2、70.2和51.7%。燃料和氧化剂的质量流量和当量比分别为20.6g/S、41.2g/S和1.7。燃烧试验中，单爆轰波在1557、1459和1353m/S处旋转，传播速度与几何阻塞率成正比增加。估算的燃料-氧化剂比冲在14 8±8 S的范围内，几何阻塞率和传播速度对该比冲的影响尚不确定。利用氧化剂真空室压力估算了氧化剂喷射器在爆震波作用下的流体动力堵塞率。结果表明，流体动力阻塞率随几何阻塞率的增大而线性减小。这一重要趋势表明，RDC的运行受限于几何阻塞率较低的区域。预测了RDC的稳定运行和增压燃烧需要在保持几何阻塞率的同时降低流体动力阻塞率。在视频率为0.5和1µS的情况下，成功地实现了包括燃气回流在内的整个RDC结构的可视化，并与可视化实验结果进行了对比，验证了估算的流体动力阻塞率的有效性。结果表明，流体动力阻塞率主要取决于燃气回流的时间尺度。
To analyze a rotating detonation cycle (RDC) with burned gas backflow, simultaneous self-luminous visualization, pressure, and thrust measurements with gaseous ethylene and oxygen were performed. Three different geometric blockage ratios (bottom-wall-surface area to cross-sectional area of combustor) were set at 89.2, 70.2, and 51.7%. The fuel and oxidizer mass flow rates and equivalence ratio were constant at 20.6 g/s, 41.2 g/s, and 1.7, respectively. During the combustion test, the single detonation wave rotated at 1557, 1459, and 1353 m/s, and the propagation speed increased proportionally for the geometric blockage ratio. The estimated fuel–oxidizer–based specific impulse was in the range of 148±8 s, and the impact of the geometric blockage ratio and propagation speeds on this specific impulse was not confirmed. The hydrodynamic blockage ratio of the oxidizer injector due to the detonation wave was estimated using the oxidizer plenum pressure. It was found that the hydrodynamic blockage ratio linearly decreased with an increase in the geometric blockage ratio. This important trend suggests that the RDC operation is limited in the region of the lower geometric blockage ratio. It is also predicted that a reduction in the hydrodynamic blockage ratio while maintaining the geometric blockage ratio is required for stable RDC operation and achievement of pressure gain combustion. Moreover, the whole RDC structure including the burned gas back flow successfully visualized at the frame rate of 0.5 and 1 µs. The validity of estimated hydrodynamic blockage ratio was demonstrated by comparison with the visualization experiment. It was concluded that the hydrodynamic blockage ratio was primarily determined mainly by the time scale of the burned gas backflow.