Numerical modelling of a segmented annular seal with enhanced lift effects

Samia Dahite (1) , Mihai Arghir (1)

1 TriboLub - Mécanique des interfaces lubrifiées [Institut Pprime]

A segmented annular seal is composed of several identical carbon segments assembled around the rotor by a circumferential (garter) spring. Each segment has one or more pads delimited by deep grooves to generate a radial lift force when the speed of rotation is not zero. One of the solutions for enhancing this lift is to provide inclined grooves on the rotor. This solution is analyzed here numerically by assuming a thin air film between the rotor and the pad of the segment. The thin air film is modeled by the Reynolds equation solved in a rotating coordinate system. The rotor is therefore considered fixed and the segment has an opposite speed of rotation. Due to the deep axial grooves separating the pads and the segments, the model is unsteady even in a rotating coordinate system. The approach enables the estimation of radial displacement, of the leakage rate and of the power dissipated in the seal as well as the influence of the nose friction force on the dynamic behavior of the segment. A second simplified approach neglects the axial grooves separating the pads. The modeled domain consists of a single pattern of inclined grooves with periodicity boundary conditions in the circumferential direction. This approach allows a rapid steady-state calculation that explains the opening of this kind of segmented seal.

Mots clés: Annular segmented seal ; Inclined grooves ; Numerical model

Domaines: Sciences de l'ingénieur [physics]

Samia Dahite, Mihai Arghir. Numerical modelling of a segmented annular seal with enhanced lift effects. Mechanical Systems and Signal Processing, 2021, 152, pp.107455 -. ⟨10.1016/j.ymssp.2020.107455⟩. ⟨hal-03492689⟩