Integrated Structure Design And Measurement Technology Of Centrifugal Impeller

As a new type of small thermal aeroengine,small turbojet aeroengine is widely used in military and civil.The function of the compressor,which is one of the three core components of the turbojet engine,is to pressurize and perform work on the gas entering the turbojet engine to meet the requirements of the combustion chamber.The centrifugal impeller is the core part of the compressor,and its quality plays a decisive role in the performance of the compressor such as the boost ratio.At present,the development level of turbojet engine’s compressors in China still has a certain gap compared with aviation powers.Therefore,it is imperative to improve the development level of compressor impellers and other components.In this paper,the centrifugal impeller of a small turbojet aircraft engine compressor in a foreign country is taken as the research object.First,the threedimensional model of the centrifugal impeller is reconstructed by reverse engineering technology,and then the strength analysis and structural optimization of the centrifugal impeller model are carried out to achieve the optimal design of the impeller.Combined with five-axis testing equipment to generate centrifugal impeller inspection path,and initially completed the online inspection experiment of impeller blades.The main contents and innovations of this article are summarized as follows:(1)The first part completes the reverse reconstruction of centrifugal impeller.Reverse engineering technology is used to process the equal-section data collected by the coordinate measuring machine,and the reverse reconstruction of the centrifugal impeller surface model is completed based on the NURBS curve and surface theory.(2)The second part accomplishes the strength calculation of centrifugal impeller.By using the finite element analysis technology,the distribution situation of equivalent stress,radial displacement and other strength parameters of the centrifugal impeller under the working condition is obtained,which verifies the usability of centrifugal impeller and provides data for the optimization of impeller structure.(3)Here the optimization design of centrifugal impeller structure is completed.Combined with the characteristics of five-axis material increasing and decreasing technology,the optimal structure and size scheme of centrifugal impeller is obtained by using topology optimization technology and size optimization technology.The mass reduction of the optimal centrifugal impeller is achieved by 20.52%under the condition of meeting the strength requirements in advance.(4)Finally,the impeller blade inspection path planning and preliminary online inspection experiment were completed.Based on the analysis of the working principle of the measurement system and the overall planning of the measurement path,an in-depth study of the distribution strategy of the measurement control points was carried out to generate a non-interference inspection path and initially complete the online inspection of the impeller blades.