ABSTRACT
Investigations on reaction turbine cascade were conducted with the aim of ascertaining
the influence of space-chord ratio on secondary flows and losses. The turbine cascade
had high deflection reaction blades with a geometric deflection of 820. Structured
hexahedral elements were used for meshing. Periodic boundary condition for periodic
faces and no slip boundary condition for endwall, blade surfaces were applied.
Experimental inlet profile was specified and the SST K-
turbulence with transition was
used for closure. Five space-chord ratios; namely, S/Ch = 0.42, 0.60, 0.70, 0.84 and
1.04 were varied at constant stagger and incidence angles. Space-chord ratio alters
blade loading influencing secondary flows characteristics. As space-chord ratio is
increased, secondary loss coefficient increases primarily due to the increased blade
loading resulting in increased cross channel deflection. Space-chord ratio influences
loss levels. There exists an optimum space-chord ratio at which total pressure losses
are minimum.