关键词: 脉冲爆轰发动机；爆轰噪声；填充系数；指向性；管间距；声压级

Abstract: The experiment system with dual-tube pulse detonation engine is designed to investigate the noise characteristic of dual-tube pulse detonation engine with different filling fractions and different detonation tube separation distances. The experimental results show that as the propagation distance increases，the detonation peak pressure decreases quickly and its decay rate reaches the highest around PDE exit. The decay rate slows down in the region of far from tube exit. With the increase of filling fraction，the detonation noise pressure increases and the detonation noise directivity slows down gradually. At the location of 400mm away from tube exit，the peak sound pressure level is 197.95dB，201.93dB and 204.51dB under the condition of 60%，100% and 140% filling fraction，respectively. At different propagation distance，the directivity changes. The highest detonation noise pressure appears in 0° direction around PDE exit and it appears in 30° direction in the region of more than 2m away from tube exit. The detonation noise shows the same directivity at different detonation tube separation distances and the directivity appears more obviously with separation distance decreases.

Key words: Pulse detonation engine；Detonation noise；Filling fraction；Directivity；Separation distances；Sound pressure level