Abstract: The effects of honeycomb cell on the discharge behavior of honeycomb seal and referenced labyrinth seal are numerically investigated based on the Reynolds-Averaged Navier-Stokes (RANS) equations and standard turbulent model using commercial CFD software ANSYS CFX. The leakage flow characteristics of the honeycomb seal at three cell sizes, three cell depths, six pressure ratios, constant sealing gap and rotational speed flow condition are analyzed. Numerical simulation results show that the leakage of labyrinth seal and that of honeycomb seal both increase with an increase in pressure ratio. The honeycomb seal with appropriate cell diameter and depth can improve its sealing performance at the same rotational speed, pressure ratio and sealing clearance. The leakage flow rate of honeycomb seal increase with increasing cell diameter at the fixed cell depth. At the same cell diameter, the leakage flow rate of honeycomb seal decreases firstly and then increases with the increase of cell depth. An improved prediction formula of leakage flow rate of honeycomb seal is presented on the basis of classical Egli equation of labyrinth seal through introducing effective seal fins coefficient and honeycomb cell structural coefficient. The reliability and accuracy of the presented prediction equation for honeycomb seal is demonstrated by the CFD computational results.

Key words: Discharge behavior, Honeycomb seal, Numerical simulation, Prediction formula