Research On Assembly Process Optimization Of RB211 Aeroengine Based On DFC Assembly Modeling Method

The background of this paper is based on investigating the problem that the RB211aero-engine vibration of High-Pressure Compressor(HPC)was overhauled by the domestic engine overhaul factory.The delivery Key Characteristics datum flow chain of high-pressure compressor was established according to the actual assembly process, and the Key Characteristics transmission path of the HPC system assembly was also systematicaly analysised.The HPC disk assembly error model was established by use of "state transfer" matrix which could calculate concentricity error for different stage rotor.The model of assembly error shows that the multi-stage rotor concentricity error accumulation and transfer was the main reason of N3 vibration.In order to reduce the concentricity error of HPC disc during assembly,the "straight-build assembly" process optimization was proposed with the goal of reducing the assembly error.By use of Monte Carlo method to verify the optimization effect of “straight-build assembly”process concentricity error index in rotor stage and available rotor assembly angle,the rotor was simulationed according to real high-pressure size. In the experiment of assembly technique, according to the relationship between the rotor assembly and optimization N3 vibration test curves, the “straight-build assembly” technology was applied in process of assembly the real RB211 engine rotor system.The results of the Monte Carlo simulation and the assembly process experiment show that the aeroengine HPC system "straight-build assembly" process can control the accumulation and transmission of errors in rotor assembly process,and reducing the impact on the key features of concentricity.It improved the quality of rotor assembly and making the occurence of N3 vibration in low level.