基于动力学分析的发动机测振截面选取

研究了发动机测振截面选择的建模方法和优化算法。确定测振截面选择思路，建立转子-支承-机匣整机模型，计算正常和故障条件下转子动力学特性，并依据总体方案规定的传感器数目，确定测振物理量较大的转子截面或支承位置，完成振动传感器布置方案的初步确定。进一步提出测振方案优化方法，通过对实测数据进行分析，考虑实测信号的信噪比和信息冗余性，确定各测点振动数据有效信息量，判定测振方案是否合理，并选择机载测点。以某型发动机为例，设计监测点布置方案。结果表明:机载测点与该型发动机实际机载传感器测点位置相同，验证了测振方案的建立方法、优化方法和机载传感器选择方法正确可靠。单元敏感度越高，反映转子振动越明显。振动相似度越低，反映发动机整机振动特性越全面。研究结果为航空发动机测振截面布置提供重要依据。 

Section selecting for engine vibration measurement based on dynamic analysis

Modeling method and optimization algorithm of vibration measurement sections selection of the engine was studied. The selection idea of vibration section was determined. The rotor-support-casing whole model was established .The rotordynamic characteristics were calculated under normal and fault conditions. And the section or bearing position of rotor in larger vibration was determined according to the number of sensors which the overall program requires. The initial layout of vibration sensor was completed. An optimization method for vibration measurement was proposed. The effective information of vibration data on each measuring point was determined by analyzing measured data and considering the signal-to-noise ratio and redundancy of measured signal. It was judged that whether the vibration measurement program was reasonable and the airborne measuring point was selected. A engine was taken as an example. The scheme of monitoring points was designed. The study showed that the airborne measuring point was the same as that of the real airborne sensor of the engine. It was verified that the establishment and optimization method and airborne sensor selection method were correct and reliable. The higher the elements sensitivity was, the more significantly the vibration of the rotor was reflected. The lower the vibration similarity was, the more completely the characteristics of engine vibration was reflected. The research result provides an important basis for the layout of vibration measurement of aero-engine.