Studies in End-loss Phenomena in Axial Flow Steam Turbine Blade Passages

Authors:

Somnath Bhattacharjee (NTPC Limited. New Delhi)

Lajpat Rai (Institute of Technology & Management, Gurgaon)

Keywords: Axial turbines, End Losses, Secondary flow, Vortices

Abstract:

Flow in axial turbines is extremely complex, three-dimensional and unsteady, resulting in high losses, reduced efficiency & poor performance. The historic breakdown of loss into 'profile loss', 'end loss'; and 'leakage loss' continues to be widely used although it is now clearly recognized that the loss generation mechanisms are seldom independent. End loss forms a major part of internal aerodynamic losses occurring in turbine. Aim of this paper is to provide an overview of work related to end loss phenomenon in turbine blade cascades. The last such review was carried out 15 years back. A more complete understanding of the complex three-dimensional flow, their origin and associated losses will certainly prove helpful in any attempt to make improvements in turbine performance.