Transient Performance Study of Compliant Foil Cylindrical Gas Film Seal With Supercritical Carbon Dioxide

Abstract A novel transient solution model for compliant foil cylindrical gas film seal utilizing supercritical carbon dioxide as the medium, taking mass eccentricity into account, has been established under the influence of combined high-speed fluid effects. This study reveals the transient operating mechanism of the seal, investigates the impact of mass eccentricity on transient behavior, analyzes the anti-interference capability of the seal under external excitation, and further determines the structural optimal range. The results show that the seal displays robust anti-interference capabilities in the presence of mass eccentricity and external excitation. The application of unidirectional excitation leads to notable fluctuations in the vicinity of the peaks of eccentricity and mass leakage rates, thereby reducing stability. In contrast, bidirectional excitation has been observed to result in significant fluctuations in sealing performance, which ultimately leads to a degradation in the system's functionality. The optimal sealing stability is achieved when the flexibility coefficient ranges from 0.001 to 0.004 and the length-to-diameter ratio is between 2.0 and 2.5.