Design And Implementation Of Aircraft Engine Blade Reconstruction Module Based On Open CASCADE

In recent years,with the rapid development of aircraft power technology in China and the construction of national defense,the next generation aircraft engine should possess ultra high speed,long endurance,ultra long range and large thrust weight ratio.As a result,the structure of aero engine becomes more and more complex,and the requirement of accuracy becomes higher and higher.Blade is the most complicated part of aero-engine,and its design quality and cost directly affect the quality and cost of the engine.The reconstruction of aero engine blade surface has a direct impact on the computational accuracy of CAM,but the CAM system also affects the overall blade processing,and the overall disc determines the performance of the aero-engine.Blade reconstruction is the basis of aero engine NC machining.Research on aero engine blade reconstruction method has greatly expanded CAD processing of industrial products,improve product design,modify and optimize the speed,saving products and industrial design in manpower and material resources.It has become one of the focuses of research that how to reconstruct the complex surface of aero engine with high precision and high quality.At present,there are many algorithms of surface reconstruction,but there are still many problems in the aero engine blade of the complex free surface modeling.First,the ill conditioned geometric model will cause the CAM to fail;Second,the accuracy of the model will affect the accuracy of the machining.In this paper,based on the previous research,combined with the specific needs of CAM computing,a surface reconstruction method based on blade cross section is proposed to realize the reconstruction of complex surfaces.The method of surface reconstruction based on blade cross section can well solve the problem that the complicated surface of aero engine cannot be calculated by CAM because of its poor precision and uneven parameters.The main idea of this method is to construct the interpolation curved face of blade section line of blade after uniform sampling,sampling point data preprocessing will value noise points in the data are removed,at the end of each section of line bounding box algorithm for turbine blade tip,the blade type value points to sort the data,then using B spline theory to reconstruct the blade,to ensure that the final fitting to generate a smooth,uniform parameters and high precision Bspline surface.Surface reconstruction is finished to evaluate the reconstruction quality by extracting the characteristic parameters of blade section line,the section line feature extraction includes turbine blade optimal circle center and radius,the maximum chord length,twist angle and blade thickness.Finally,combined with a specific example given by the Research Institute,the design and implementation of aero-engine blade reconstruction module are carried out with the open-source geometric kernel platform Open CASCADE.The experimental results show that the surface of the reconstructed surface is smooth,uniform and accurate,and meets the requirements of the original design model.It provides a great help for the subsequent CAM calculation.