Rotordynamic characteristics prediction for scallop damper seals using computational fluid dynamics

• Published in: Chinese journal of aeronautics Vol. 35; no. 8; pp. 92 - 106
• Main Authors: ZHANG, Wanfu, YIN, Lu, YANG, Li, TIAN, Haoyang, LI, Chun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2022; School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China%Electric Power Research Institute of State Grid,Shanghai Municipal Electric Power Company,Shanghai 200437,China
• Subjects: Computational Fluid Dynamics (CFD); Effective damping; Rotordynamic characteristics; Scallop damper seal; Stability; Scallop damper seal; Computational Fluid Dynamics (CFD); Stability; Effective damping; Rotordynamic characteristics; Rotordynamic characteris-tics; Computational Fluid Dynamics(CFD)
• ISSN: 1000-9361
• DOI: 10.1016/j.cja.2021.11.016

Enhancing damping characteristic is one of the effective methods to solve the instability problem of the rotor system. The three-dimensional numerical analysis model of scallop damper seal was established, and the effects of inlet pressures, preswirl ratios, rotational speeds, interlaced angles and seal cavity depths on the rotordynamic characteristics of scallop damper seal were studied based on dynamic mesh method and multi-frequencies elliptic whirling model. Results show that the direct stiffness of the scallop damper seal increases with decreasing inlet pressure and increasing rotational speed and cavity depth. When the seal cavity is interlaced by a certain angle, which shows positive direct stiffness. The effective damping of the scallop damper seal increases with the increasing inlet pressure, the decreasing preswirl ratio and the rotational speed and cavity depth. There exists an optimal interlaced angle to maximize the effective damping and the system stability. The leakage of the scallop damper seal is significantly reduced with decreasing inlet pressure. The preswirl will reduce the leakage flowrate, and the rotational speed has a slight effect on the leakage performance. The leakage of the scallop damper seal decreases with increasing seal cavity depth.