The experiment system of pulse detonation engine is set up to investigate on influence of diameter on detonation acoustic characteristic. The research of detonation acoustic characteristic of pulse detonation engine for four different diameters in different angles is carried out. Results from the test show that as the PDE diameter increasing, there are increases in amplitudes of impact noise in all angles, and the growth rate of amplitude of impact noise in the 90° direction is generally greater than that in the 0° direction. The smaller PDE diameter is, the distance of most obvious directivity at 0° turning to most obvious directivity at 30° is shorter. When the distance is shorter, such as 200 mm, the duration of detonation acoustic is increasing with the increase of PDE diameter, however, when the distance is longer, such as 3000 mm, it is just the opposite. The maximum duration of detonation acoustic is appeared in 3000 mm under 30 mm PDE diameter which reaches to 1.44 ms.

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直径对脉冲爆震发动机爆轰声特性的影响研究

建立了脉冲爆震发动机实验系统，研究了直径对爆轰声特性的影响。对四种不同直径，不同角度的脉冲爆震发动机的爆震声学特性进行了研究。测试结果表明，随着PDE直径的增加，冲击噪声的幅度在各个角度上都有所增加，并且冲击噪声的幅度在90°方向上的增长率通常大于在0°方向上的增长率。PDE直径越小，则0°时最明显的方向性向30°时最明显的方向性的距离越短。当距离较短时（例如200 mm），爆轰声的持续时间随PDE直径的增加而增加，但是，当距离较长时（例如3000 mm），相反。在30 mm PDE直径下达到1.44 ms的情况下，爆炸声的最大持续时间为3000 mm。