【摘要】 针对冲压发动机地面直连式试验推力测量数据振动现象,利用LabWindows/CVI编程对实际推力测量试验数据进行了频谱分析;探讨了进气管路失稳条件,给出了横向振动固有频率,采用有限元方法对波纹管进行了模态计算。分析表明所述振动问题主要诱因为垂向波纹管的横向振动与轴向波纹管轴向振动,提出了改进方案,多次发动机热试验验证了分析结果的正确性。更多还原

【Abstract】 Aiming at the vibration problem of thrust measurement data in ramjet-motor ground testing,spectrum analysis of practical data with Windows/CVI program was conducted.The instability condition of pipes was discussed and the intrinsic frequency of transverse direction in pipes was deduced.The modal of bellow was studied under different conditions with FEM,and the results show that the key reasons of the described problem is due to cross-oscillation of the vertical-bellows and axial vibration of the axial bellows.Some suggestions were also proposed.Test results are in excellent agreement with those of the available analytical solution.更多还原