喷管摆动角度和频率对SRM中压力振荡响应特性的影响

Effects of Angle and Frequency of Nozzle Swing on Pressure Oscillation Response in Solid Rocket Motors

喷管摆动可能会诱发燃烧不稳定性,而不稳定性问题已经受到了国内外研究人员的高度重视。为了研究喷管摆动角度和频率对燃烧室内压力振荡响应的影响,采用数值模拟方法,在给定某时刻装药燃面、喉径和正弦摆动方式下,对不同摆角和摆频下的发动机燃烧室压强变化规律及喷管摆动过程的响应规律进行数值分析。研究表明:固定摆动频率,改变摆动角度,燃烧室内平均压力都随时间小幅度上升,摆动角度为3°和7°时,平均压强增量较其它角度而言较为明显;固定摆动角度,随着摆动频率的增加,喷管摆动引起燃烧室内低频响应幅值在增加;由喷管摆动所引起的燃烧室压力振荡频率主要集中在100Hz以下的低频区。

The instability of the combustion may be induced by the swing of the nozzle,and the problem of instability has been paid great attention by the researchers at home and abroad. To investigate the effects of the swing angle and frequency of nozzle on pressure oscillation in combustion chamber,the analysis on the pressure variation and response law under different swing angle and frequency in combustion chamber of solid rocket motors has been conducted by numerical simulation,on the condition that the burning area of grain and throat diameter are given at certain time and the swing method is fixed on sine. The results show that on condition of the fixed swing frequency,when the swing angle is changed,the average pressure of combustion chamber increases slightly with time. When the swing angles are 3° and 7°,the average pressure increment is more pronounced than the other angles. With the increase of the swing frequency,the amplitude of low frequency response caused by the swing of nozzle is increasing under the same swing angle. Pressure oscillation caused by swing nozzle is mainly concentrated in the low frequency region below 100 Hz.