Nucleating unsteady flows in low-pressure steam turbine stages

Abstract

The present paper deals with the detailed numerical investigation of transonic, turbulent, unsteady two-phase steam flows with internal heat addition after partial condensation of the working fluid. The observed phenomena include homogeneously, homogeneously-heterogeneously and heterogeneously dominated condensation effects. The results concerning the different condensation mechanisms are initially discussed in terms of the turbulent, transonic flow through Laval nozzles. Further, an interesting phenomenon of nucleation and droplet growth inside turbulent boundary layers is presented. Application to transonic turbine flows in the rotor cascade VKI-1 shows the influence of homogeneous nucleation on the turbulent shock-boundary layer interaction. Finally, the different types of condensation models were compared to investigate the two-dimensional transonic two-phase flow in an entire turbine stage including high-frequency rotor-stator interactions.

Keywords

nucleating unsteady flows low-pressure steam turbine stages turbulent boundary layers condensation models transonic two-phase flow rotor-stator interactions

Get full access to this article

View all access options for this article.

References

Dibelius

Mertens

Pitt

Strauf

Tropfenbildung in Dampfturbinen. Brennstoff-Wärme-Kra¹ft (BWK), 1989, 41(6), 283–287.

Lindsay

Behaviour of impurities in steam turbines. J. Pwr Engng, 1979, 101, 68–72.

Stastny

Sejna

Numerical modelling the flow with parallel homogeneous and heterogeneous condensation in steam turbine cascades. In Proceedings of ABB Seminar on Condensing Flows in Steam Turbines, Baden, Switzerland, 1997.

Stastny

Sejna

Numerical analysis of heterogeneous condensation of the steam flowing in turbine cascade. In IMechE, Conference Transcript on Turbomachinery, 2-5 March 1999, Vol. B (Professional Engineering Publishing, Bury St Edmonds and London).

Peters

Meyer

K. A. J.

Measurement and interpretation of growth of monodispersed water droplets suspended in pure vapour. Int. J. Heat Mass Transfer, 1995, 38, 3285–3293.

Young

J. B.

The condensation and evaporation of liquid droplets in a pure vapour at arbitrary Knudsen number. Int. J. Heat Mass Transfer, 1997, 34, 1649–1661.

Gyarmathy

Zur Wachstumsgeschwindigkeit kleiner Flüssigkeitstropfen in einer übersättigten Atmosphäre. Z. Angew. Math. Physik, 1963, 14, (3), 280–293.

Heiler

Instationäre Phänomene in homogen/heterogen kondensierenden Düsen- und Turbinenströmungen. Dissertation, Fakultät für Maschinenbau, Universität Karlsruhe, 1999.

White

A. J.

Young

J. B.

Walters

P. T.

Experimental validation of condensing flow theory for a stationary cascade of steam turbine blades. Phil. Trans. R. Soc. Lond. Ser. A, 1996, 354, 59–88.

10.

Chen

W. L.

Sliding grids for rotor-stator interaction. In Proceedings of the 8th Biennial CFD Colloquium, UMIST, 1998, pp. 31–40.

11.

Winkler

Heiler

Schnerr

G. H.

Instabilities in condensing turbine flows. In Proceedings of Fourth ISAIF-Fourth International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, Dresden, Germany, 1999, pp. 269–284.

12.

Winkler

Heiler

Schnerr

G. H.

Homogeneous/heterogeneous condensation dynamics in turbulent low pressure turbine flows. In Proceeding of International Conference SYMCOM99, Cieplne Maszyny Przeplywowe, Turbomachinery, No. 115, ?odz, Poland, 1999, pp. 445–456.

13.

Winkler

Schnerr

G. H.

High-speed flows with condensation. In Proceedings of AMIF-ESF Workshop on Computing Methods for Two-Phase Flows, Centre Langevin, Aussois, France, 12-14 January 2000.

14.

Schnerr

G. H.

Heiler

Winkler

Steady and unsteady condensate formation in turbomachinery-blade to blade flow and rotor stator interaction. In Proceedings of Third International Conference on Multiphase Flow, ICFM 1998 (Eds Bataille

Joia

), Lyon, France, 8-12 June 1998, pp. 42–58 (also Multiphase Flow Sci. Technol., 10(4), 349-368).