Influence of Geometry on Rotordynamic Coefficients of Brush Seal

Abstract

It has been observed that the geometry of a brush seal has a significant effect on the sealing performance. However, the relationship between rotordynamic coefficients and geometry factors of the brush seal itself are rarely considered. In this article, the rotordynamic coefficients of a typical single-stage brush seal for different geometries and operating conditions were numerically analyzed using CFD RANS solutions coupled with a non-Darcian porous medium model. The reaction force which plays an essential role in rotordynamic coefficients was obtained by integrating the dynamic pressure distribution. The influence of the bristle pack thickness, fence height, clearance size and other working condition parameters on aerodynamic force, stiffness coefficients, and damping coefficients of brush seal were presented and compared. In addition, the effects of various geometric configurations on pressure and flow features were also discussed.

Leakage performance predictions of a brush seal based on fluid–solid coupling method

“…In the fluid-solid coupling calculation, the main calculation module used is system coupling that transfers the data between solid model and fluid model ( Figure 4). 24 To ensure the information transfer between solid and fluid models on the coupling surface without generating negative volume grids in the mesh deformation, tetrahedral cells are used in both solid and fluid domains. In the finite element (FE) calculation, nitrogen is used as the fluid medium and the RNG k-e turbulence model is adopted, then the boundary conditions are set, which includes the pressure and temperature of inlet and outlet, the fluid solid coupling surface and dynamic mesh, the step of time, and the number of time steps.…”

“…In the fluid–solid coupling calculation, the main calculation module used is system coupling that transfers the data between solid model and fluid model ( Figure 4 ). 24 …”