The Effect of the Front Plate with Ribs on Brush Seal Flow Characteristics

Abstract

In highly inlet swirling environment, the bristles of brush seal tend to circumferentially slip, which may lead to aerodynamic instability and seal failure. In this paper, a new structure of front plate with ribs was designed to reduce the influence of high inlet swirl on bristle pack, and a three-dimensional porous medium model was used to simulate the brush seal flow characteristics. The effects of the geometric parameters of ribs, including inclined angle (-20º-40º), spacing (5mm-15mm) and height (0.5mm-1.5mm) on the pressure and flow fields as well as the leakage behavior were investigated. Results show that the ribs structure can effectively regulate and control the upstream flow pattern of the bristle pack, inducing the swirl flow into radially inward, which results in decreased circumferential velocity component. The ribs with inclined angle of 20 degree, height of 2mm and spacing of 5mm were observed to have the best effect on reducing inlet swirl and improving the brush seal stability.