The impact of rotor labyrinth seal leakage flow on the loss generation in an axial turbine

• Published in: Proceedings of the Institution of Mechanical Engineers. Part A, Journal of power and energy Journal of power and energy, 2005-09, Vol.219 (6), p.481-490
• Main Authors: Anker, J E, Mayer, J F, Casey, M V
• Format: Article
• Language: English
• Subjects: Applied sciences; Effects; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fluid dynamics; Leakage; Marine; Mechanical engineering; Turbines; Turbulent flow
• ISSN: 0957-6509; 2041-2967
• DOI: 10.1243/095765005X31081

Abstract This paper examines the impact of labyrinth seal leakage flow over the rotor shroud on the loss generation in an axial turbine stage. Numerical studies have been carried out with an in-house solver using the Baldwin-Lomax turbulence model to identify the changes in secondary flow structures. The code has been validated for this application using test data from a low-speed axial turbine stage with a simple generic rotor shroud labyrinth seal. Numerical simulations are carried out with different clearance gaps (0, 1, and 3 mm) and without cavity wells. The simulations are used to distinguish the separate interactions of the main flow with the leakage flow and the cavity flow. The leakage flow causes a strong increase in the secondary flow kinetic energy in the downstream stator. Both the leakage flow and the cavity flow lead to an increase in the secondary kinetic energy in the rotor.