Abstract: Based on gas dynamic lubrication and heat transfer theory, the theoretical analysis model for aero thermoelastic multi-field coupling of compliant foil cylindrical gas film seal used in aero-engine is established by considering the viscosity-temperature effect and foil elasticity deformation. The distribution law of the film temperature, velocity field, and the working condition parameters' role in the maximum film temperature are studied. The influence law of the viscosity-temperature effect on the pressure field and the role of the mechanism of sealing performance changes at high temperatures are explored. The results indicate that when the foil cylindrical gas film seal is operated at high speed, the film temperature increases significantly due to the effect of gas stirring heat, the maximum temperature difference is more than 400℃, and the impact of viscous force is more significant at high temperature, the film pressure increases by 13.8%; the highest film temperature is mainly located in the radial intermediate layer along the direction of the film thickness, and high temperature area is concentrated in the region of the minimum film thickness, the overall performance of the symmetry is stronger; within the range of the parameters, the increase of rotational speed and eccentricity leads to the rise of film temperature by 25.7%, but the film temperature decreases by 18.2% with the rise in inlet pressure; the film floating force and friction torque at high temperatures increase by 33.1% and 51%, respectively, and the mass leakage rate and the eccentricity angle decrease by 62.5% and 25.7%, respectively.

Key words: cylindrical gas film seal, compliant foil, thermal effect, aero thermoelastic multi-field coupling, sealing performance