Experiments were conducted to investigate the windage heating characteristics in real size models of stepped labyrinth seals.The change in total temperature across the labyrinth seal was measured in a high speed test facility at different pressure ratios (1.05-2.8)

relative sealing clearances(2.4-4.0)

Reynolds numbers(1900-28000) and rotational speeds (0-12000r/min).Based on the experiments

the renormalization group (RNG) k-ε turbulence model was used to compute the windage heating characteristics of the same stepped labyrinth seals.The results indicate that the temperature rise decreases with the increases of pressure ratio

Reynolds number and relative sealing clearance

and it increases with the increase of rotational speed.In addition

the numerical simulation satisfies the experiment.The most of the windage heating takes place in the first half of the seals

and the value of temperature rise is about 60% in the first two tooth chambers.An empirical expression for the windage heating coefficient was obtained and it fits the experimental results well.