Comparison of the flow characteristics for the honeycomb and labyrinth seal using numerical simulation

Three-dimensional flow characteristics of the honeycomb seal and labyrinth seal for steam turbines are investigated by solving Navier-Stokes equations. The finite volume method is used to discretize the Navier-Stokes Equations. The standard k-ε two equations turbulence model is used to close the solving equations. The second order upwind scheme and the first order upwind scheme are applied to solve convection and diffusion terms respectively. The obtained results demonstrate that the seal leakage flow rate of the honeycomb seal is smaller than that of the labyrinth seal at the same flow condition. The leakage flow field of the honeycomb seal is divided into many small vortex flows due to its structure. The kinetic energy of the leakage flow can be transferred into heat energy efficiently. This leads to decrease the seal leakage flow rate of the honeycomb seal. This study can be able to supply the theoretical foundation and technical support for the engineering application of the honeycomb seal for steam turbines.