A transient bulk flow model with circular whirl motion for rotordynamic coefficients of annular seals

作者：Xia Peng^*; Liu Zhansheng; Yu Xiangyu; Zhao Jingming

来源：Chinese Journal of Aeronautics, 2018, 31(5): 1085-1094.

DOI：10.1016/j.cja.2018.02.011

• Annular seals
• Bulk flow
• Computational Fluid Dynamics (CFD)
• Rotordynamic
• Turbulence

Bulk flow model with perturbation simplification has been used to calculate rotordynamic coefficients in annular seals which have significant influences on the dynamic behavior of rotors in turbomachinery. In this work, a transient bulk flow model with arbitrary rotor motion is developed, and the boundary conditions and friction factor in the model are calibrated with steady Computational Fluid Dynamics (CFD) analysis. The numerical solution scheme is developed based on the finite element method to obtain the transient reaction force in the seal clearance. With a periodic circular rotor orbit, the transient forces at multiple whirling frequencies are used to evaluate the rotordynamic coefficients. The leakage flowrate of CFD analysis has good agreement with experimental results and the calibrated parameters in bulk flow model are dependent on operating conditions. Although CFD calibration improves the accuracy of the perturbed bulk flow model, the direct damping is overestimated and the cross-coupled damping is underestimated. Compared with the perturbed model, the predictions of the transient bulk flow model are more agreeable with the experiment.

• 出版日期2018-5
• 单位哈尔滨工业大学