Abstract:The effect of the rub groove structure of seal surface on three dimensional (3 D) flow field and leakage flow rate of the rub groove labyrinth seal was researched by using computing hydrokinetics software, RNG k-ε model, Simple algorithm and structural gridding under different conditions of the clearance, the pressure ratio and the rotational speeds. The results show that the groove seal structure can realize the full gas kinetic energy dissipation, thus it can block the gas flow and reduce the gas leakage effectively.The leakage flow of labyrinth seal is increased with the increase of the clearance, but both the amount and the rate of leakage of the rub groove labyrinth seal are less than the common labyrinth seal. Along with the rise of pressure ratio, the leakage flow of rub groove labyrinth is increased, but in a reducing gradient compared to the common labyrinth seal. Along with the increase of rotational speed, rub groove labyrinth seal are more likely to form the effect of cyclone in the rub-groove, so that the seal performance is improved significantly.