The Theoretical Study For The Cause Of The Aero Engine Tip Clearance And The Development Of The Data Analysis System

In the current aircraft engine design and test, maintaining good tip clearance becomes an important means to improve the performance of the engine. On the operation of the engine, the good tip clearance can reduce the working medium leakage and the loss of the end wall to improve engine performance. Improve efficiency in reducing the tip clearance, at the same time, it may also lead to the transfer stator rub, directly affecting flight safety. So keeping good clearance fit in flight has a very important practical significance and engineering value on improving engine performance and reliability.The subject comes from national security major basic research projects tasks of Shenyang 606 Institute of AVIC. In this paper, firstly, aircraft engine rotor and stator tip clearance testing technology development status and data processing methods are summarized and analyzed. Secondly, rotor and stator gap single-sensor single-step mathematical model has been deduced. The mathematical model of the rotor and stator least squares center method is established. The tip clearance-related parameters FIR, IMP and the mathematical model of the tip clearance relative to the center square are established. And the model for eliminating effects of the subsidence is also established when the engine is placed horizontally. According to the values from the above model and foreign mature software-Linipot software comparing and analyzing, the absolute error is less than 0.001, the relative error is less than 0.005%. Therefore it can be concluded this theoretical studies results are correct, the theoretical model established and Linipot’s are consist. Thirdly, this article also developed the engine tip clearance data analysis software on the LabVIEW platform. The software has the function with real-time data processing, auto-save, report printing, data query and the gap enlarged display. Fourthly, in this paper, three translocation single sensor error separation method and time domain non-opposing two sensor error separation method mathematical model are derived. And the separation of the two methods has been simulated on LabVIEW and analyzed its separation accuracy in-depth.In addition to the modeling and system development, this paper also does some basic research work. It Sums up a single sensor repeatedly transposition method to accurately measure conditions and parameter selection rules and proposes a complete extraction method of least squares center coordinates location. The relationship between the weight function and the surface profile of the stator in the radial direction of the variation of distortion has been researched and the interaction has been summed up.