In axial turbomachinery such as low pressure turbines, shrouded airfoils with labyrinth seals are commonly used. Among different sealing options, labyrinth seals in particular are characterized by long term durability and high sealing efficiency. Since a leakage flow is inevitable, a thorough understanding of how the leakage flow exits the cavities, its interaction with the main flow, and the induction of losses is necessary. In order to take into account unsteady effects, three-dimensional time resolved RANS computations of a 1.5 stage LPT rig in its design operating point are conducted. To capture effects in the boundary layer, a low Reynolds approach is used at the blade surface as well as on the hub and tip surfaces. To match the real geometry of the turbine blades, fillets have been modeled. Simulations were performed using the TRACE solver developed by the German Aerospace Center (DLR). The investigation shows how cavity flows have a significant influence on the main-flow aerodynamics and the loss generation. Steady and unsteady results with full spatially discretized cavities show a significant decrease of isentropic efficiency compared to simulations without cavities. The efficiency drop for the steady and time-averaged cavity computations can be explained with intensified secondary flow. The time resolved calculation shows a strong non-uniformity of the leakage flux depending on the instantaneous circumferential position of the up- and downstream blades. The time dependent ingress of cavity leakage results in the formation of a counter-rotating vortex pair. In terms of the influence on the main flow, it is shown that the interaction is limited to the end walls with almost no influence on the midspan flow.
Skip Nav Destination
ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition
June 6–10, 2011
Vancouver, British Columbia, Canada
Conference Sponsors:
- International Gas Turbine Institute
ISBN:
978-0-7918-5467-9
PROCEEDINGS PAPER
Time-Resolved Numerical Investigation of the Interaction of Labyrinth Seal Leakage and Main-Flow in a 1.5-Stage LP Turbine
Marc H.-O. Biester,
Marc H.-O. Biester
Leibniz University Hannover, Hannover, Germany
Search for other works by this author on:
Lasse Mueller,
Lasse Mueller
Leibniz University Hannover, Hannover, Germany
Search for other works by this author on:
Joerg R. Seume,
Joerg R. Seume
Leibniz University Hannover, Hannover, Germany
Search for other works by this author on:
Yavuz Guendogdu
Yavuz Guendogdu
MTU Aero Engines GmbH & Co.KG, Mu¨nchen, Germany
Search for other works by this author on:
Marc H.-O. Biester
Leibniz University Hannover, Hannover, Germany
Lasse Mueller
Leibniz University Hannover, Hannover, Germany
Joerg R. Seume
Leibniz University Hannover, Hannover, Germany
Yavuz Guendogdu
MTU Aero Engines GmbH & Co.KG, Mu¨nchen, Germany
Paper No:
GT2011-45883, pp. 1623-1632; 10 pages
Published Online:
May 3, 2012
Citation
Biester, MH, Mueller, L, Seume, JR, & Guendogdu, Y. "Time-Resolved Numerical Investigation of the Interaction of Labyrinth Seal Leakage and Main-Flow in a 1.5-Stage LP Turbine." Proceedings of the ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. Volume 7: Turbomachinery, Parts A, B, and C. Vancouver, British Columbia, Canada. June 6–10, 2011. pp. 1623-1632. ASME. https://doi.org/10.1115/GT2011-45883
Download citation file:
42
Views
0
Citations
Related Proceedings Papers
Related Articles
Investigation of Three-Dimensional Unsteady Flows in a Two-Stage Shrouded Axial Turbine Using Stereoscopic PIV—Kinematics of Shroud Cavity Flow
J. Turbomach (January,2008)
Aerothermal Investigations of Tip Leakage Flow in Axial Flow Turbines—Part II: Effect of Relative Casing Motion
J. Turbomach (January,2009)
Turbine Tip and Shroud Heat Transfer
J. Turbomach (July,1991)
Related Chapters
Aerodynamic Performance Analysis
Axial-Flow Compressors
Boundary Layer Analysis
Centrifugal Compressors: A Strategy for Aerodynamic Design and Analysis
Siphon Seals and Water Legs
Hydraulics, Pipe Flow, Industrial HVAC & Utility Systems: Mister Mech Mentor, Vol. 1