Study On Virtual Instrument For Blade Tip-timing Acquiring System

Rotating machinery,as the key equipment which has been widely used in national economy and national defense projects.The performance of rotating blades affects the security and credibility of rotating machinery.Therermore analyzing and monitoring vibration signals of the rotating blades is an effective method for detecting the faults of blades.The paper focus on using virtual instrument to design professional instrument called blade tip-timing system which based on Blade Tip-timing method and it is used to analysis the vibration performance parameters.After designing and accomplishing the testing experiment,good results has been obtained which validate the correctness of the system.The main work of the thesis is as follows:(1)Firstly, this paper introduces the mechanism and force analysis of blades and types of blades.Natural frequency of blade has been introduced and vibrational model has been set up by vibration theory.Thus we get the cambel graph of rotating blade.Next the Blade tip-timing theory has been introduced.The blade tip-timing system include sensors, data acquisition card and virtual instruments has been discussed.(2)Secondly,according to the virtual instrument development process, we design and develop the blade tip-timing acquiring system. First of all, get the list of the instrument function requirements, and then we develop the system frame, main interface, several functional modules. Thus we completed an efficient, good human-computer and rather convenient virtual instrument. Finally several test data were made to find if the system could run in the right way or not and the results indicate the virtual instrument makes it.(3)Applied to blade test rig experimental analysis, the results shows that the acquring system achieves the good results, and the virtual instrument is practicality and proved correct.