基于高速摄影的烟火药水下燃烧喷口气泡与噪声研究

基金项目:

2009年江苏省普通高校研究生科研创新计划项目(CX09B_105Z)和国家部委基金资助项目(51305090302)。

详细信息

Study on the bubble and noise of exit from pyrotechnic composition combustion underwater base on high speed photoeraphy

1 School of Chemical Engineering, Nanjing University of Science & Technology Nanjing 210094;
2 School of Equipment Engineering, Shenyang University of Science & Technology Shenyang 110159

摘要: 为分析烟火药水下燃烧的现象及声辐射特性,采用高速摄影技术,对烟火药水下燃烧喷口处的气泡进行了实验研究。在此基础上根据高速摄影的系列图像估计了气泡体积,通过对气泡体积的曲线进行拟合后再求二阶导数获得了其变化的加速度,基于脉动体积源点声源公式,计算了喷口噪声的声压。结果表明由于界面的Bjerknes力和浮力的作用,气泡主要呈现一种扁球体;烟火药水下燃烧喷口噪声的声压最高达到了177.1 Pa。

Abstract: In order to analyze the characteristics of the acoustic radiation and phenomenon of the pyrotechnic composition combustion underwater,the high speed photography has been used to study the behavior of the bubble at exit, which was generated by the pyrotechnic composition combustion underwater.The bubbles' volume were estimated with high speed film sequences,and their change acceleration were obtained by getting second-order derivative through the fitting curve of the bubble-volume,then the sound pressure of the noise were calculated based on the equation of point sound source of pulsation volume.Results show that the bubbles were mainly flattened sphere,because of the effects of the Bjerknes and buoyancy force on the interface,when the pyrotechnic composition is combusting underwater,the sound pressure of the noise from the exit is up to 177.1 Pa.