Session: 14-06 Compliant Seals

Paper Number: 127753

127753 - Investigation of Grooved Front Plate for Inlet Swirl Reduction in Brush Seals 

Brush seals are plausible replacements for conventional labyrinth seals in gas turbines for managing internal air system flows and leakages. They can offer superior leakage performance compared to labyrinth seals due to their compliant nature, and a reduced effective clearance during operation. Despite their improved sealing performance, highly swirling flow and aerodynamic forces on the upstream bristles could lead to aero-elastic instability within the bristle pack. This study investigates a means of improving brush seal robustness in high-shaft speed locations by reducing the inlet swirl that is incident on the bristle pack. Grooved swirl-reducing features are evaluated as a means of achieving this, and to minimise the amount of machining and waste material. A parametric study including five different parameters, length, depth, width, pitch, and angle was conducted. This identifies the most sensitive parameters for swirl reduction and demonstrated that the performance of ribs from previous research can be replicated and improved upon. A Design of Experiments (DOE) approach is adopted to investigate alternative groove design geometries. Combining a horizontal channel with an inclined groove enables a higher pitch to achieve the same swirl reduction.  Adding these features to the traditional front plate improves brush seal robustness and in particular reduces the effects of aerodynamic forces which could drive bristle pack instabilities.

Presenting Author: Abdullah Abbas University of Surrey

Presenting Author Biography: Abdullah Aboseada is a PhD candidate at the University of Surrey working under the supervision of Dr Michael Pekris and Professor John Chew. His research interests are in swirl reduction and fluid-structure interaction modelling in brush seals.

Authors:

Abdullah Abbas University of Surrey
Michael J Pekris University of Surrey
John Chew University of Surrey