Research On Fast Reconstruction Method For Blade Profile Surface Of Aero-engine Based On Measurement Data

Blade is the core component of aero engine,and its high performance design and precise manufacturing is the key technologies to ensure the aerodynamic performance,reliability and stability of blades.Researching the reverse reconstruction technology and constructing the accurate three-dimensional model of the blade surface have important guiding significance for the reverse design,adaptive processing and quality evaluation of the blade profile.In the view of fact that the precision of the reconstructed surface is still low and the reconstruction process is complicated,which make it difficult to meet the requirements of high-performance design and mass manufacturing for blades at present.In order to shorten the design cycle of blade surface,improve the surface machining accuracy,enhance engine performance,this paper focuses on the high efficiency and high precision reconstruction method of aero engine blade profile,and develops a software system which dedicated to the reconstruction and quality analysis of the blade profile.It has laid a technical foundation for realizing the rapid,high-precision and high-quality reconstruction of the blade surface.The main contents of this paper are as follows:(1)The main measuring method are compared and analyzed,and the scheme of blade profile detection based on coordinate measuring machine is established.Combined with the structural characteristics of measurement data,the methods of measurement data denoising,probe radius compensation and data registration are proposed.It provides accurate measurement data for the subsequent 3D model reconstruction of blade profile.(2)The basic mathematical models of free curves and surfaces are studied.The definition and properties of Bezier,B spline and NURBS theory are compared.Combined with the requirement of actual blade surface reconstruction,a blade profile interpolation reconstruction scheme based on NURBS theory is proposed.In addition,the smoothing method of wavelet decomposition is applied to fairing the cross-section curve and surface of the blade.This method improves the construction accuracy and smooth performance of the blade reconstruction model,and realizes the high quality reconstruction of the blade surface.(3)Based on the Open Geometry Library,a software system dedicated to the reconstruction and quality analysis of the blade profile has been developed.The system includes read interface,corresponding cross-section curve and surface reconstruction function module for CMM measurement.It can quickly realize the high precision reconfiguration of the blade surface based on the CMM measurement data.And in the quality analysis module of the system,an adaptive triangular mesh model with node layers feature and a visual analysis method of main machining error of blade surface was proposed.It can visually and accurately visualize the blade profile error,the distortion error,the swept deformation error,and the bending deformation error.Finally,based on the traditional reverse engineering software,a system functional verification experiment is carried out,and the results show that the function of the blade model reconfiguration and the quality analysis of the software has better pertinence and accuracy.