Critical condition of inner cylinder radius for sustaining rotating detonation waves in rotating detonation engine thruster
Critical condition of inner cylinder radius for sustaining rotating detonation waves in rotating detonation engine thruster
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DOI：
10.1016/j.proci.2018.07.070
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发表时间：
2019
影响因子：
3.4
通讯作者：
A. Kawasaki;Tomoya Inakawa;J. Kasahara;Keisuke Goto;K. Matsuoka;A. Matsuo;I. Funaki
中科院分区：
文献类型：
--
作者：
A. Kawasaki;Tomoya Inakawa;J. Kasahara;Keisuke Goto;K. Matsuoka;A. Matsuo;I. Funaki
我们描述了用于太空火箭推进的旋转爆震发动机（RDE）的内缸半径维持足够的推进器性能所需的临界条件。使用气态C2 H4和O2作为推进剂，我们测量了RDE的推力和冲量实验，改变内筒半径从31 mm（典型的环形配置）到0（无内筒配置），同时保持外筒半径（ro= 39 mm）和推进剂喷射器位置（rinj= 35 mm）恒定。在实验中，我们还对燃烧室和发动机羽流中的自发光进行了高速成像。在相对大的内圆柱半径（ri= 23和31 mm）的情况下，燃烧室中的旋转爆震波附着于内圆柱表面，而对于相对小的内圆柱半径（ri= 0、9和15 mm），观察到旋转爆震波从内圆柱表面脱离。在这些小的内半径的情况下，在羽流中观察到强烈的化学发光，可能是由于烟灰的存在。另一方面，对于ri = 15、23和31 mm的情况，在正确扩张时，比冲大于理想值的80%。同时，对于casesri= 0和9 mm，比冲低于理想扩张值的80%。这被认为是由于在小内圆筒半径情况下观察到的不完全爆震燃烧（爆燃燃烧）。我们的研究结果表明，在我们的实验条件下，ri= 15 mm接近维持旋转爆轰在一个合适的状态，有效的推力产生的临界条件。内圆筒半径的这种情况对应于未燃烧层高度降低到4.5-6.5的情况。
We describe the critical condition necessary for the inner cylinder radius of a rotating detonation engine (RDE) used for in-space rocket propulsion to sustain adequate thruster performance. Using gaseous C2H4and O2as the propellant, we measured thrust and impulse of the RDE experimentally, varying in the inner cylinder radiusrifrom 31 mm (typical annular configuration) to 0 (no-inner-cylinder configuration), while keeping the outer cylinder radius (ro= 39 mm) and propellant injector position (rinj= 35 mm) constant. In the experiments, we also performed high-speed imaging of self-luminescence in the combustion chamber and engine plume. In the case of relatively large inner cylinder radii (ri= 23 and 31 mm), rotating detonation waves in the combustion chamber attached to the inner cylinder surface, whereas for relatively small inner cylinder radii (ri= 0, 9, and 15 mm), rotating detonation waves were observed to detach from the inner cylinder surface. In these small inner radii cases, strong chemical luminescence was observed in the plume, probably due to the existence of soot. On the other hand, for cases whereri= 15, 23, and 31 mm, the specific impulses were greater than 80% of the ideal value at correct expansion. Meanwhile, for casesri= 0 and 9 mm, the specific impulses were below 80% of the ideal expansion value. This was considered to be due to the imperfect detonation combustion (deflagration combustion) observed in small inner cylinder radius cases. Our results suggest that in our experimental conditions,ri= 15 mm was close to the critical condition for sustaining rotating detonation in a suitable state for efficient thrust generation. This condition in the inner cylinder radius corresponds to a condition in the reduced unburned layer height of 4.5–6.5.