Effects of sealing clearance and stepped geometries on discharge and heat transfer characteristics of stepped labyrinth seals

摘要

The effect of sealing clearance and step geometries on the discharge and heat transfer characteristics of the stepped labyrinth seals with honeycomb and smooth lands was investigated. The Reynolds-averaged Navier-Stokes equations coupled with standard k-w turbulent model were adopted and numerically solved. The heat transfer coefficient as well as the discharge coefficients and meridian flow fields were calculated at two kinds of sealing clearance of stepped labyrinth seals and compared to the experimental data. The obtained results show that the present three-dimensional periodic model and numerical approach can give a good prediction of the discharge behaviour and heat transfer coefficients for both smooth labyrinth seal and honeycomb seal. Moreover, a range of HI C_r (step height to clearance) and t_s/ t (step axial position to pitch) were conducted to investigate the sealing clearance and step geometries on the discharge and heat transfer characteristics of the stepped labyrinth seal with smooth and honeycomb lands. The detailed leakage flow and heat transfer coefficients distributions and corresponding influence mechanisms in stepped labyrinth seals were also illustrated and discussed.