论文信息 - Lateral Forces From Single Gland Rotor Labyrinth Seals in Turbines

Lateral Forces From Single Gland Rotor Labyrinth Seals in Turbines

Even though interest in labyrinth seal flows has increased recently, an analytical model capable of predicting turbine flow response to labyrinth seals is still lacking. Therefore, this paper presents a new model to predict flow response in an axial turbine stage with a shrouded rotor. A concentric model is first developed, and this model is used to develop an eccentric model. Basic conservation laws are used in each model, and a non-axisymmetric sealing gap is prescribed for the eccentric model. Thus, the two models can predict the evolution of a uniform upstream flow into a non-uniform downstream flow. In turbines with concentric shrouded rotors, the seal flow is retarded in the axial direction and tangentially underturned. In turbines with eccentric shrouded rotors, flow azimuthally migrates away from and pressure reaches its peak near the maximum sealing gap region. Finally, the rotordynamic implications of such flow non-uniformities are discussed and compared against eccentric unshrouded turbine predictions.Copyright © 2002 by ASME

Bum Ho Song | Seung Jin Song

[1] Y. J. Qiu,et al. Prediction of destabilizing blade tip forces for shrouded and unshrouded turbines , 1985 .

[2] Steven R. Manwaring,et al. Endwall Cavity Flow Effects on Gaspath Aerodynamics in an Axial Flow Turbine: Part I — Experimental and Numerical Investigation , 2000 .

[3] Ge´za Vermes,et al. A Fluid Mechanics Approach to the Labyrinth Seal Leakage Problem , 1960 .

[4] Seung Jin Song,et al. Rotordynamic Forces Due to Turbine Tip Leakage: Part I—Blade Scale Effects , 1997 .

[5] John D. Denton,et al. The Control of Shroud Leakage Flows to Reduce Aerodynamic Losses in a Low Aspect Ratio, Shrouded Axial Flow Turbine , 2000 .

[6] J. S. Alford,et al. Protecting Turbomachinery From Self-Excited Rotor Whirl , 1965 .

[7] Christian Lerner,et al. The Influence of the Clearance of Shrouded Rotor Blades on the Development of the Flowfield and Losses in the Subsequent Stator , 2000 .

[8] Dara W. Childs,et al. SELF-EXCITED VIBRATION IN HIGH-PERFORMANCE TURBOMACHINERY , 1984 .

[9] Seung Jin Song,et al. Rotordynamic Forces Due to Turbine Tip Leakage: Part II—Radius Scale Effects and Experimental Verification , 1997 .