过载条件下固体发动机声能共振规律研究

Research on acoustic energy resonance of SRMunder overload condition

从声学角度出发,将粒子阻尼转化为声腔介质的声衰减系数,探究不同过载条件下固体发动机粒子阻尼对声学特性的影响规律,以声学响应传递函数评估发动机声不稳定性;通过划分不同计算域,计算各区域粒子阻尼及对应声衰减系数,并将其添加到声场中进行声学计算;对比分析了过载为3 g、6g、9g、12g、15g工况下粒子的空间分布特性及声学响应变化规律。结果表明,在粒径不变的前提下,随着横向过载的不断增加,发动机内粒子空间分布的不均匀性显著增加,各监测点声学响应传递函数随横向过载的增大呈增大趋势,表明在横向大过载下,粒子阻尼对发动机内压力振荡的抑制作用减弱,这对发动机稳定性极其不利;在同一工况下,发动机头部声学响应值高于喷管喉部附近,将对声不稳定产生消极影响。

From the perspective of acoustics,particle damping was transformed into acoustic attenuation coefficient of sound cavity medium,and the influence rule of particle damping on acoustic characteristics of solid rocket motor(SRM)under different overload conditions was explored,and the acoustic response was used to evaluate the acoustic instability of the SRM.By dividing different computational domains,particle damping and corresponding acoustic attenuation coefficients in each region were calculated and added to the sound field for acoustic calculation.The spatial distribution characteristics and acoustic response variation of particles under the overload conditions of 3 g,6 g,9 g,12 g and 15 g were compared and analyzed.The results show that:Under the premise of constant particle size,the spatial distribution of particles in the SRM increases significantly with the increase of transverse overload,and the acoustic response transfer function of each monitoring point increases with the increase of transverse overload,indicating that the damping effect of particle damping on the pressure oscillation in the SRM is weakened under large transverse overload,which is extremely unfavorable to the stability of the SRM.Under the same working condition,the acoustic response value of the engine head is higher than that near the nozzle throat,which will have a negative influence on the acoustic instability.