摆动喷管轴向激励对燃烧室压力振荡影响的数值研究  

Numerical study on the effect of movable nozzle axial excitation on chamber pressure oscillation

作　　者：王革[1] 苏成志 杨海威 关奔[1] WANG Ge;SU Chengzhi;YANG Haiwei;GUAN Ben(College of Aerospace and Civil Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]哈尔滨工程大学航天与建筑工程学院,哈尔滨150001

出　　处：《固体火箭技术》2022年第1期76-82,共7页Journal of Solid Rocket Technology

摘　　要：固体火箭发动机工作时,摆动喷管受到伺服力和气动力等载荷的共同作用,在轴向上会产生小幅度的振动,振动频率与燃烧室内腔轴向声频耦合时会造成压力振荡幅值增大,诱发不稳定燃烧,导致燃烧室内压力、燃速不均等情况的出现。应用数值方法研究了摆动喷管轴向激励对燃烧室压力振荡的影响,分析了压力振荡对喷管轴向激励幅值和频率的响应规律,以及燃烧室内的声压分布特征。结果表明,当喷管以燃烧室内腔固有频率做轴向振动时,会诱发燃烧室内的非线性不稳定燃烧,其稳定的极限振幅远高于其他激励频率下压力振荡幅值;喷管振动频率一定时,燃烧室内各点压力振荡幅值随喷管振动幅值增大而线性增大;持续的轴向激励使燃烧室呈现出驻波声场的特征,压力分布不均,波腹处声压达到0.14 MPa,约为燃烧室总压的2%。Small amplitude vibration can be generated in the axial direction when the movable nozzle of an operating solid rocket motor is subjected to the interaction of servo and aerodynamic forces.This vibration may be coupled with the intrinsic axial acoustic frequency of the chamber,inducing combustion instabilities featured by non-uniform pressure distribution and combustion rate.The pressure responses inside the chamber under excitations at different amplitudes and frequencies were numerically studied.The characteristics of acoustic pressure distribution inside the chamber were demonstrated.The results show that nonlinear unstable combustion is induced when the nozzle vibrates at the chamber intrinsic frequency and its stable limit circle is much higher than the pressure oscillation amplitude at any other excitation frequencies.When the nozzle vibration frequency is constant,the amplitudes of the pressure oscillation at each monitoring point inside the chamber increases linearly with the increase of the nozzle vibration amplitude.The continuous axial excitation causes standing acoustic wave inside the chamber,where the acoustic pressure at the antinode reaches 0.14 MPa,approximately 2%of the chamber total pressure.

关 键 词：固体火箭发动机 不稳定燃烧 摆动喷管 数值仿真 

分 类 号：V435[航空宇航科学与技术—航空宇航推进理论与工程]