A Method to Determine the Circumferential Sliding of the Intershaft Gas Film Seal Considering Centrifugal and Thermal Expansion Effects

The paper presents a method for predicting the circumferential relative sliding between the seal ring and the outer rotor in the dual-rotor aero-engine intershaft seal under high temperature and high-speed conditions. A criterion is proposed for determining the circumferential sliding of the intershaft end-face gas film seal, taking into account the effects of centrifugal expansion and thermal expansion. The mechanical mechanism of the circumferential sliding between the seal ring and the outer rotor is investigated. The expansion of the seal ring and the outer rotor is simplified to a plane thermo-elastic mechanical problem, and the expansion and deformation of the two parts are calculated. The influence of material characteristics, temperature difference, and initial interference on the expansion deformation and connection relationship of the seal ring and outer rotor is analyzed. Moreover, the critical sliding speed region between the seal ring and the outer rotor is determined. The analysis method provides theoretical guidance for predicting the circumferential sliding of the seal ring in practical engineering applications.