摘要
针对浸液离心轮结构,提出一种非接触式模态特性识别技术,给出浸液介质对离心轮湿模态影响的量化表征。利用三维激光多普勒测振系统实现结构测点拾振,并在浸液结构中充分考虑不同介质引起的激光折射效应,采用LMS模态分析系统实现模态特性识别。非接触式模态特性识别技术获得的离心轮模态特性与常规成熟加速度传感器测试结果保持很好的一致性,该项识别技术能够很好地运用于浸液结构模态特性识别。开展离心轮在水和液氧模拟介质下模态特性测试,浸液介质导致结构频率不同程度的下降,但在不同阶次上的影响可以保持很好的一致性,不同液位浸液介质对结构模态特性表现出不同的影响规律。
To identify modal characteristics of a centrifugal impeller immersed in fluid, a new non-contact modal identification technique was proposed to study effects of fluid on wet modes of the impeller. A 3 D laser Doppler vibration measurement system was used to realize a structure’s vibration measurement at its measured points. Laser refraction effects caused by different media were fully considered in vibration measurement of the immersed structure. Modal identification was conducted using LMS modal analysis system. It was shown that the impeller’s modal characteristics obtained with the non-contact modal identification technique agree well with those measured using conventional mature acceleration sensors, so the proposed non-contact modal identification technique can be well used in immersed structures’ modal identification. Wet modal characteristics of the centrifugal impeller immersed in water and liquid oxygen analog medium were measured with this non-contact method. The results showed that fluid mediums cause decrease in the impeller’s natural frequencies to different extents, their effects on different orders of the impeller’s natural frequencies can be well consistent;the influence of dipping medium at different liquid level on the modal characteristics of the impeller is different.
作者
霍世慧
黄道琼
黄红
任武
宣统
HUO Shihui;HUANG Daoqiong;HUANG Hong;REN Wu;XUAN Tong(National Defense Key Laboratory of Science and Technology on Liquid Rocket Engines,Xi’an 710100,China;Xi’an Aerospace Propulsion Institute,Xi’an 710100,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2019年第7期15-19,41,共6页
Journal of Vibration and Shock
基金
国家重大基础研究项目(613321)
关键词
浸液离心轮
湿模态
模态特性识别
非接触式测振
centrifugal impeller immersed in fluid
wet mode
modal identification technique
non-contact vibration measurement