Experimental investigation on the influence of bristle lay angle on the leakage characteristics of low hysteresis brush seals

The leakage characteristics and hysteresis effect were experimentally studied on three test pieces of a low hysteresis brush seal with bristle lay angles of 40°, 45°, and 50°. The results showed that under the same conditions, the leakage coefficient is the largest and smallest when the bristle lay angles are 50° and 45°, respectively. The leakage coefficient increases significantly when the bristle lay angle exceeds 45°. The leakage coefficient increases with pressure differential and then is almost unchanged when it exceeds 0.2 MPa. When the rotating speed increases, the leakage coefficient decreases slightly. The rising and dropping of pressure differential caused a distinct leakage hysteresis effect, which is the weakest when the bristle lay angle is 45°. In addition, the hysteresis effect in a rotating state is weaker than that in a static state. The hysteresis effect due to rising and dropping of rotating speed is very weak with a pressure differential of 0.1 MPa. As the pressure differential increases to 0.3 MPa, the hysteresis effect is slightly enhanced. The overall performance is optimal when the bristle lay angle is 45°.