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http://dx.doi.org/10.9725/kts.2021.37.1.31

Analysis of the Axial Thrust Force of a Centrifugal Impeller with a Thrust Labyrinth Seal at its Backside  

Park, Jun Hyuk (Graduate School, Graduate School, Dept. of Mechanics and Design, Kookmin University)
Kim, Tae Ho (School of School of Mechanical Engineering, Kookmin University)
Publication Information
Tribology and Lubricants / v.37, no.1, 2021 , pp. 31-40 More about this Journal
Abstract
This study describes the effects of a thrust labyrinth seal applied to the backside of a centrifugal impeller on the axial thrust force for high speed turbomachinery. The bulk flow model using Neumann's equation calculates the seal cavity pressures and leakage flow rate of the thrust labyrinth seal based on three configurations: teeth-on-rotor (TOR), teeth-on-stator (TOS), and interlocking labyrinth seal (ILS). Prediction results show that the ILS is superior to the TOR and TOS in terms of leakage flow rate. A mathematical model of a centrifugal impeller with a thrust labyrinth seal on its backside calculates the force components corresponding to the impeller inlet, shroud, impeller backside outer, backside seal, and backside inner pressures. A summation of the force components renders the total axial thrust force acting on the centrifugal impeller. The Newton-Raphson numerical scheme iteratively calculates the pressures and leakage flow rate through the impeller wall gap. The prediction results reveal that the leakage flow rate and total axial thrust force increase with rotor speed, and the ILS significantly decreases the leakage flow rate, whereas it slightly increases the axial thrust force when compared to TOR and TOS. Increasing the seal clearance causes an increase in the leakage flow rate and a slight decrease in the axial thrust force with the ILS.
Keywords
labyrinth seal; leakage flow rate; pressure drop; axial thrust force; centrifugal impeller;
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Times Cited By KSCI : 1  (Citation Analysis)
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