小孔喷注消声器在宇航设备上的应用

宇航设备中的供氧排气系统在排气过程中产生了很高的喷注噪声,小孔喷注消声器是控制喷注噪声的有效措施。以喷注噪声理论为基础,利用小孔喷注消声器设计方法,为宇航设备供氧排气系统喷口设计小孔喷注消声器。设计中通过限制孔间距要求,降低孔径,实现了小孔喷注消声器的高降噪效果。加工消声器并测试,降噪效果理想。喷注噪声的计算和实测结果对比显示,两者吻合良好,误差在2 dB(A)左右,但驻压比为4时,计算结果与实测结果相差较大,分析原因是喷口后附加喇叭口结构对喷注噪声中的冲击噪声产生了影响,而经典计算公式并未考虑此种情况。小孔喷注消声器在宇航设备供氧排气系统中应用的可行性和小孔喷注消声器设计方法的可靠性得到了验证。

Application of Small Hole Injection Silencer on Aerospace Equipment

High injection noise, which can be controlled effectively by a small hole injection silencer, is produced during the exhaust process of the oxygen supplying and exhaust system in the aerospace equipment. Based on the injection noise theory, a small hole injection silencer was designed for the nozzle of the oxygen supplying and exhaust system. In the design, the hole diameter was reduced by limiting the hole spacing requirement, and the high noise reduction of the small hole injection silencer was achieved. The noise reduction performance of the silencer was measured and proved to be satisfactory. The comparison between the injection noise results calculated and measured showed a good agreement. Most of the errors are about 2dB(A), while the error for case with standing pressure ratio being 4 is quite big. The reason for this might be that the additional horn structure after the nozzle has a large influence on the impact noise concluded in the injection noise, which the classical calculation formula could not take into account. Both the feasibility of the small hole injection silencer using in aerospace equipment and reliability of the design method were verified in the design and application.