Abstract: A runner for use as retrofit in existing Francis turbine water path includes a set of nine profiles covering crown (hub) to skirt (band) area is to produce power efficently at deteriorated head condition of site. Each of the nine profiles is made of two curves, namely pressure and suction curves, meeting at two ends denoted as leading and trailing edge points. The runner exhibits better performance at specific speed value (ns,m) from 83 to 98, than the existing runner.

Abstract: The present invention relates to design of new runner to suit an existing Francis turbine water path. It is designed to meet performance at reduced head hence suitable for higher unit discharge and unit speed than originally designed. The blade of runner comprises a set of nine profiles covering crown to skirt and the profiles have distinct geometrical parameters. Computational fluid dynamic (CFD) based studies exhibit that the runner has better performance features for existing water path; both in terms of efficiency of pressure distribution for a range of unit discharge q11=170-240 litres/second and unit speed n11=56-72 rpm; or alternatively for specific speed range ns, m=83-98.

Abstract: The present invention relates to the aerodynamic design of moving blades, pertaining to later stages of axial steam turbines where the inlet flow is non-uniform over the blade height. The claim made herein is a set of six invented transonic blade profiles which can be used to develop various type of 3D twisted blades for axial steam turbine. The aerodynamic characteristics of these 6 base profiles are evaluated herein as a function of stagger angle and pitch/chord ratios. The aerodynamic characteristics invented herein is for a group of six base profiles which are to be used for creation of three dimensional blades made of varying cross-sections and twisted over the blade height while ensuring the centers of gravity of these sections lie in a radial line. Each of the blades, sections from hub to tip is twisted differently from desired outlet angle.

Abstract: The present invention relates to the improved aerodynamic design of a pair of blade profiles valid over a wide range of flow regime. The so formed blades, pertain to high pressure, intermediate pressure and first few stages of low pressure cylinders of axial steam turbines. The invented blades cover a wide range of stagger angles; pitch/chord ratios; inlet flow angles and outlet Mach numbers.

Abstract: This invention relates an improved cylindrical blades for axial steam turbines comprising a leading edge and a trailing edge and a pressure face and a suction face and an inlet flow angle and an outflow flow angle at the leading edge and trailing edge respectively characterized in that the blades formed by setting angle variation for incompressible flow as well as at subsonic Mach numbers at the exit with a lower loss for a range of stagger angles.

Abstract: The invention relates to an improved three dimensional blade for axial steam turbine comprising a leading edge with inlet flow angle and a trailing edge with an outflow angle a pressure face, suction face and a chord which is the line connecting the leading and trailing edge and the betabi the stagger angle formed to the intersect ion of said chord and U-axis wherein the blade is made of varying cross-sections of profiles and and leaned such that the center of gravity of mid sections are shifted opposite to the direction of blade rotation and the blade sections from hub to tip are twisted to a gradual manner.