Abstract:The influence of honeycomb cell size on leakage flow in honeycomb seal under different conditions of the clearence,the pressure ratio,and the rotational speed was numerically simulated by using the Fluent software,RNG kε twoequation turbulence model,Simple algorithm and structural griddings.The results show that the honeycomb seal with special hexagonal structure can divide the leakage flow into many small vortices,where the threedimensional anticlockwise turbulent spirals can be seen.The greater the honeycomb cell size is,the more the leakage rate becomes.Under the same seal clearance,with the increasing of honeycomb cell size,the increasing gradient of leakage rate is increased.With the increasing of pressure ratio,the leakage rate is increased,but in a reducing gradient.Along with the increasing of rotational speed,the rubgroove labyrinth seal are more likely to form the strong effect of cyclone,which is beneficial to block the leakage flow.