Annular seal destabilizing force reduction with circumferential flow suppression using multi-arch teeth. (December 2021) - Zhang, Mingjie
Abstract: In turbomachines, the tangential force caused by the circumferential flow of the fluid inside annular seal is the origin of the fluid-induced vibration. To reduce the tangential force, this paper proposes the multi-arch seal to suppress the circumferential flow of fluid. Inside the multi-arch seal, several arch regions are formed along the circumferential direction. Flow separation, vortex, and reverse circumferential flow are generated to suppress the circumferential flow. Numerical results show that the multi-arch seal reduces largely the tangential force with a similar leakage flow rate compared with the labyrinth seal. Geometry parameter analysis shows that increasing arch number and reducing axial gap between two arch crowns reduce the tangential force, but have little influence on the leakage flow rate. Highlights: A novel multi-arch seal is designed to suppress the circumferential flow. Flow separation, vortex, and reverse circumferential flow are generated. The multi-arch seal largely reduces the destabilizing tangential force. The multi-arch seal performs well in improving rotor stability.