The Micro Turbojet Engine Rotor Dynamics Research

As a kind of power propulsion system with high energy density ratio, Micro turbojet engine (MTE) is characteristic with high thrust-weight ratio, small size and high speed, etc, and it plays an increasingly vital role in various types of unmanned aerial vehicles, cruise missiles and other mini-aircrafts. Not only that, it also will have significant research values and application prospects in the future. As a crucial component of MTE, the rotor system will be more and more attractive and concerned by people. Its stability and dynamic performance affects the working state and service life of the engine directly. Therefore, the study of rotor system of MTE has an importantly scientific significance and engineering value.In this dissertation, development status of MTE and its rotor dynamic research at home and abroad was introduced. The structural feature of the MTE rotor system was analyzed and three-dimensional model was established with Pro/E software, which was then imported into finite element software ANSYS to get the finite element model. Based on modal analysis theory, some inherent characteristics were obtained by calculating the natural frequency and mode shapes in the static state. The dynamic characteristics were simulated when the engine works, and theoretical results were compared with the results obtained by ANSYS to ensure the feasibility of ANSYS calculation, and then performance changes and force conditions of the rotor were analyzed at the condition of spinning. The result shows that the critical speed in spinning state is larger than that in static state.The unbalance of rotor in the practical work was simulated, and harmonic response analysis of typical working conditions was studied. The results could be a reference for the balance of a rotor. According to the principle of rotor balancing, combined with the structure, the rotor was simplified as a mechanical model, and then theoretical balance analysis was carried out using the appropriate balancing method and balancing precision.