脉冲爆轰发动机爆轰噪声场区域划分及其数值模拟

The Classification and Numerical Calculation of Noise Propagation outside Pulse Detonation Engine

为了探究脉冲爆轰发动机(PDE)爆轰噪声的传播机理,根据爆轰噪声不同的非线性强度,将PDE爆轰噪声传播区域划分成强非线性区、弱非线性区和线性区3个部分,并分别采用不同的方法对各部分所对应的3种不同控制方程进行求解。数值模拟结果表明:爆轰噪声峰值声压级在出口处迅速衰减,随着轴向距离的增加,衰减速度逐渐放缓;在强非线性区,衰减速度最大值可达33 d B/m;在弱非线性区,最小衰减速度为1.02 d B/m.模拟结果对PDE爆轰噪声的传播特性研究具有参考价值。

The propagation of detonation noise is divided into three regions based on the nonlinear intensity to explore the mechanism of the noise propagation out of pulse detonation engine（ PDE）,which are strongly nonlinear region,weak nonlinear region and linear region. Three methods are used to solve the corresponding control equations. The calculated result shows that the detonation noise amplitude decays quickly at the jet. The rate of decay decreases with the increase in radial distance. The largest rate of decay is 33 d B / m in the strongly nonlinear region while the least rate of decay is 1. 02 d B / m in the weak nonlinear region. The results are of great significance for studying the mechanism of detonation noise.