The leakage characteristics and hysteresis effect of different axial width of pressure relief chamber of 0

04 mm and 06 mm with the conventional and low hysteresis brush seals were studied under the static and dynamic tests of pressure difference rise and drop and the rotor speed rise and drop. The results showed that: the dynamic leakage coefficient was about 14%-20% lower than the static one

when the pressure drop was more than 02MPa. The sealing performance of low hysteresis brush seals was better

and the leakage coefficient was up to about 20% lower than the conventional brush seal. The hysteresis effect was the strongest in the process of pressure difference rise and drop cycle with the static condition when axial width of pressure relief chamber was 06 mm. The hysteresis effect of conventional brush seal was the strongest in the process of pressure difference rise and drop cycle with the dynamic condition. After the rotor speed rise and drop cycle

the leakage coefficient decrease by about 15% when the axial width of pressure relief chamber was 06 mm

and there was basically no hysteresis effect when the axial width was 04 mm. In addition

for the three structures

the brush seal with the axial width 04 mm had the best sealing performance and the weakest hysteresis effect.