流致振动激光多普勒测振方法研究

An Investigation of Laser Doppler Vibrometer Measurement Technique on Flow-Induced Vibration

流致振动是导致反应堆零部件失效的重要原因之一,测量获得堆芯狭小空间内复杂条件下零部件流致振动情况对反应堆安全设计至关重要,本文通过实验研究流体介质中物体振动的测量方法和测量精度,探索采用激光测振仪进行流致振动测量的方法.实验采用加速度传感器和激光多普勒测振仪进行了三种不同工况下的对比试验,将激励源给定的振动外加到试验件上,通过计算机采集相关振动信号.实验表明,加速度传感器和激光测振仪测量所得振动速度有较好的一致性,但随着频率的增加,测量相对误差变大.实验表明,进行水环境下振动测量时需要对激光多普勒信号进行水的折射率的补偿修正.

In nuclear engineering, flow-induced vibration is one of the most important factors which leads to failure of reactor components. Measuring the flow induced vibration of the reactor core compo- nents within a small space under complex operation conditions is the key to reactor design. Laser Doppler Vibrometer （LDV） as a non-invasive vibration measurement technique is investigated and devel- oped to perform such flow-induced vibration measurement. In this experiment, comparison tests be- tween an acceleration sensor and the LDV instrument under three different conditions are performed. The experimental results show that two vibration measurement techniques agree well with each other on the vibration velocity measurement, a higher vibration frequency will increase the measurement error. In addition, LDV measurement values should be modified when the measured objective is immersed in water.