Effect of thermal barrier coating on thermal load of the rotor of the small aviation wankel engine

Abstract

Due to its high-altitude, low-temperature, high-load, and air-cooled working environment, small aviation rotary engines have problems such as large component load and low heat dissipation efficiency. As the main moving part of the engine, the rotor is continuously exposed to the complex temperature field of the engine. As an effective high-temperature protective coating, the thermal barrier coating can isolate the heat load generated by the work of the combustion chamber and effectively improve the complex work condition of the triangular rotor. This paper takes the triangular rotor of a small aviation Wankel engine as the research object, and establishes the finite element model of the rotor and the coating. The engine thermodynamic simulation model is established by Simulink, and the combustion chamber temperature and heat transfer coefficient are calculated. The heat transfer coefficients of the other surfaces of the rotor were calculated by series thermal resistance, which were used as boundary conditions for finite element analysis of the rotor and the coating. The temperature field, stress field and deformation of the rotor before and after processing the thermal barrier coating are compared. The results showed that after the thermal barrier coating, the temperature of the rotor will drop by about 50K on average. The temperature of the pit and cooling hole of the rotor will drop by 17K and 16K respectively, and the temperature of the inner edge and side end surface of the sealing groove will drop by about 10K. The stress values at the inner side of the rotor seal groove, the inner cavity cooling hole, and the inner hole of the rotor are reduced by about 35.4MPa, 29.4MPa, 33.4MPa, respectively, and the stress value at the bonding layer is 150MPa, which is significantly higher than the stress value at the corresponding position of the original rotor, indicating that there is stress Concentration phenomenon. At the same time, the deformation at both ends of the rotor seal groove is reduced from 61.92μm to 52.55μm, and the difference in the axial deformation of each position is less than 3mm. It can be obtained that the thermal barrier coating can effectively reduce the radial deformation of the rotor and has little effect on the axial deformation of the rotor.