Development of Higher Operation Technique in Pulse Detonation Engine (PDE)

为了在脉冲爆震发动机(PDE)中获得更高的工作效率，燃料(氢)与空气在短时间内混合并点火是非常重要的，因为爆轰波是在距离点火器很近的地方产生的。为此，研制了带有旋转阀和PDE性能的脉冲爆震发动机。在本研究中，通过改变燃料和氧气的混合方法、混合的吹扫方法和喷射方法来缩短爆轰诱导时间。结论总结如下。1)由于增加了氢在空气中的穿透距离，减少了喷射孔，从而促进了燃料和空气之间的混合。2)采用了三种不同类型的板来促进混合，但安装板对更高的操作影响不大。从耐久性的角度来看，安装板法是不必要的。3)将喷油孔的数目改为2个和4个，这样两个孔更有利于稳定地产生爆轰波。4)为了缩短爆震诱导距离，在PDE中插入螺旋线的轮廓是重要的，这是由PDE管的直径决定的。在本研究中，在螺距为10 mm的情况下，可以缩短爆轰诱导时间。5)所研制的PDE可以在40赫兹的工作频率下工作。指出PDE管应采用冷却方式，以获得较高的工作频率。

In order to obtain higher operation in Pulse Detonation Engine (PDE), it is of importance to get mixing between fuel (hydrogen) and air in a short period, and to ignite, since the detonation wave is produced in a short distance from the igniter. Therefore, the pulse detonation engine was developed which is equipped a rotary-valve and performance of PDE. In this study, experiments are conducted to shorten the detonation induction time by changing a mixing method between a fuel and oxygen, a purge method and injection method of mixing. Conclusions are summarized as follows. 1) A mixing between fuel and air is promoted by decreasing an injection hole, since a penetration distance of hydrogen into the air is increased. 2) Three types of plate to promote the mixing were applied, however the effects of installing plate on higher operation is small. It was found that installing plate method is not necessary from the endurance point of view. 3) The number of fuel injection hole is changed as two and four, thus the two holes is preferable to produce the detonation wave stably.4) In order to shorten the detonation induction distance, the contour of spiral inserted into the PDE is important which is determined from the diameter of the PDE tube. In this study, the detonation induction time is decreased in a case that pitch of spiral is 10 mm.5) The developed PDE can be operated in an operation frequency of 40 Hz. It was pointed out that the PDE tube should be equipped with a cooling method to obtain higher operation frequency.