Gas Dynamic Face Seal Tightness Under Non-Stationary Loading

Abstract

Aircraft engines have multiple operation modes for different flight conditions. However, each element of an engine is generally designed for one particular operating mode (maximum load or maximum duration). Mode alteration leads to the variation of pressure and temperature in sealing cavities. Therefore, it is important to consider the full load range into the design process of separate units. This paper presents an original technique of leakage calculation for the spiral-grooved mechanical gas face seal on the different operation modes of the aircraft engine. This type of seal has never used in aircraft engine design. However it has a history of excellent performances in comparison with the traditional type of seals, such as labyrinth or face contact seals. The value of sealing rings deformation must be determined for all operation modes. The flow model of the gas face seal is used to define heat transfer coefficients of seal ring surfaces. Using transient analysis, the influence of the load change rate on the sealing rings can be determined. The developed technique investigates the effect of the engine operating mode alteration on the temperature loads and deformations. Results of the simulation are compared with the experimental data.