摘要
针对冲压发动机尾喷口动力学设计需求,采用试验测试与数值计算相结合的手段,对其固有模态和振动环境特征进行了研究,进而对其振动设计进行了评估。结果表明,尾喷口在2 kHz频率范围内,具有丰富的固有频率成分,振型表现为整体或前端局部的壳式振动;在燃烧室出现燃烧振荡后,尾喷口将增加78.125 Hz的窄带激励能量及其倍频成分;燃烧振荡激励的3、4、7倍频分别与尾喷口的第1、2、3阶固有频率接近,可能引起结构的共振,在实际工作中应给予充分重视。
According to the requirements of dynamic design for a certain outlet used in the ramjet engine, both experiments and numerical study were performed to obtain the inherent modes and the excitation characteristics, and then the dynamical evaluation was also carried out based on the results. The results show that there were several modes within 2 kHz for the outlet, and all modes exhibited as typical shell mode shapes. When the oscillating combustion occurred, there were 78. 125 Hz and its multiple frequen- cies for the excitation energy. The 3, 4 and 7 times of the basic frequency for the oscillating combustion were similar with the 1 st, 2nd and 3rd natural mode frequencies, therefore the harmful resonances might occur, which should be noticed in the actual operation.
出处
《战术导弹技术》
2014年第4期58-62,共5页
Tactical Missile Technology
关键词
冲压发动机
振动特性
模态试验
壳体
ramjet engine
dynamic characteristics
mode test
shell
