双爆轰管脉冲爆轰发动机近场噪声特性的试验研究

Experimental Study on Acoustic Behavior of Dual-Tube Pulse Detonation Engine in Near Field

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

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

摘要:

为研究双管脉冲爆轰发动机近场爆轰噪声特性，设计了双管脉冲爆轰发动机爆轰噪声试验测试系统，对不同填充率、不同管间距下的爆轰噪声进行了测量。试验结果表明:随着传播距离的增加，爆轰噪声峰值声压逐渐减小。PDE管口附近，爆轰噪声峰值声压衰减速度最快；距离管口较远位置处，衰减速度逐渐减小。随着填充系数的增加，爆轰噪声逐渐增大，指向性逐渐变缓；距离管口400mm处，60%，100%和140%填充系数下峰值声压级依次为197.95，201.93和204.51dB。不同传播距离处，爆轰噪声指向性不同。当距离管口较近时，爆轰噪声最大值出现在0°方向；距离管口大于2m的区域内，最大值出现在30°方向。不同管间距情况下，爆轰噪声呈现出相同的指向性。管间距越小，爆轰噪声的指向性越明显。

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.