CLIAMS:We claim:
1) A high pressure blade (120) of a fluid flow machine comprising an airfoil portion formed by a convex suction side (122) and a concave pressure side (124) bounded at the extreme ends by a leading edge (126) and a trailing edge (128), wherein the geometry defining parameters of the high pressure blade (120) profile are according to the following table:
Parameter Hub Section(H-H)
Chord 19.78 mm
Inlet Angle 11.68 deg
Exit Angle -72.8 deg
Leading edge radius 3 mm
Stagger Angle -38.66 deg
Trailing edge radius 0.098 mm
Unguided turning 14.56 deg
Angle of Attack -38.66 deg
Area 9.26 mm2
Axial chord(width) 14.18 mm
Camber 84.48 deg
Maximum Thickness 4.88 mm
Pitch/Chord 0.8214
Radius at CG 300 mm
Solidity 1.217
Throat/Pitch 0.2879
Tmax/Chord 0.2485

2) A high pressure nozzle (140) of a fluid flow machine comprising an airfoil portion formed by a convex suction side (142) and a concave pressure side (144) bounded at the extreme ends by a leading edge (146) and a trailing edge (148), wherein the geometry defining parameters of the high pressure nozzle (140) profile are according to the following table:

Parameter Hub Section(H-H)
Chord 19.78 mm
Inlet Angle - 11.68 deg
Exit Angle 72.8 deg
Leading edge radius 3 mm
Stagger Angle 38.66 deg
Trailing edge radius 0.098 mm
Unguided turning 14.56 deg
Angle of Attack 38.66 deg
Area 9.26 mm2
Axial chord(width) 14.18 mm
Camber -84.48 deg
Maximum Thickness 4.88 mm
Pitch/Chord 0.8214
Radius at CG 300 mm
Solidity 1.217
Throat/Pitch 0.2879
Tmax/Chord 0.2485

3) A high pressure blade (120) of a fluid flow machine as claimed in claim 1, wherein said high pressure blade (120) is capable of achieving flat efficiencies at different sets of boundary conditions.

4) A high pressure nozzle (140) of a fluid flow machine as claimed in claim 2, wherein said high pressure nozzle (140) is capable of achieving flat efficiencies at different sets of boundary conditions.

5) A high pressure blade (120) of a fluid flow machine as claimed in claim 1, wherein said high pressure blade (120) is a cylindrical blade.

6) A high pressure nozzle (140) of a fluid flow machine as claimed in claim 2, wherein said high pressure nozzle (140) is a cylindrical blade.

7) A high pressure blade (120) of a fluid flow machine as claimed in claim 3, wherein said different sets of boundary conditions are in standard high pressure module range.

8) A high pressure blade (120) of a fluid flow machine as claimed in claim 1, wherein said fluid flow machine is a steam turbine.

9) A high pressure blade (120) of a fluid flow machine as claimed in claim 1, wherein said high pressure blade (120) can be used in wide mega watt range of steam turbines thereby reducing cost and time involved in blade development.

10) A high pressure blade (120) of a fluid flow machine as claimed in claim 3, wherein said flat efficiencies are in the range of 88% to 90%.
,TagSPECI:FIELD OF THE INVENTION:
The present invention relates to a blade of a fluid flow machine. Particularly, the present invention relates to a high pressure blade of a steam turbine.

TERMINOLOGY AND FORMULAS USED:
U-Peripheral velocity of rotor;
C-Steam velocity;
Ct-Tangential steam velocity;
Ca-Axial Steam velocity; and
Delta h- Enthalpy change.

The formulas employed in doing mean line calculations are as follows:
1)Loading factor-Delta h/U2
2)Peripheral velocity of rotor (U)= 3.147*D*N/60000 m/s
Where D=Rotor Hub Dia; N=speed of rotor in rpm.
3)Steam velocity C- 44.7 *(Delta h)0.5
4)Height of the blades in a stage (H)= 2 Q/3.147*D*sina*e*C
Where Q=Volumetric flow rate in each stage (m3/sec);
D= Rotor Hub Dia;
a= Blade or Nozzle Inlet angle;
e=Degree of admission(Projected Area of nozzles/Total area of moving blades);
C=Steam velocity.
5)Flow Coefficient= Ca/U

DEFINITIONS OF TERMS USED:
Incidence: Incidence is defined as an optimum point on the blade for the flow to hit in order to generate maximum efficiency.

Meridional Plane: A plane cutting the turbo machine through diametric line and longitudinal axis.

Pitch: Circumference of the blade (2*Pi*r)/No.of blades in a row. Circumference of the blade depends on blade height (i.e., at hub, mean or tip).

Stage: Stage herein refers to a combination of rows of blades and nozzles.

Reaction: Enthalpy drop across the rows of blades/ Enthalpy drop across the stage.

Spanwise Reaction: Reaction across different cross-section of blade length.

BACKGROUND OF THE INVENTION:
Steam turbines comprises a plurality of blades typically configured in three modules viz High pressure module (HP), Intermediate pressure module (IP) and Low pressure module (LP). High pressure module (HP) of a steam turbine typically contributes to one-third of power generation and comes immediately after control stage (nozzle chest- a row of nozzles and a row of impulse blades). Typically, conventional steam turbines employ either a straight parallel-sided blades (cylindrical) or tapered and twisted blades configuration. The criteria for selection of cylindrical blade or tapered and twisted blade depend on the height of the blade. The general design rule traditionally followed in the industry is that, if the height of the blade exceeds 110mm, taper and twist is required for the blade to achieve good efficiency and better incidence respectively. The number of rows of blades in each module of the turbine is determined depending on various factors like space, pressure ratio, power output and efficiency.

High Pressure (HP) Module, Intermediate Pressure (IP) module and Low Pressure (LP) module can be of impulse type or reaction type or combination of impulse and reaction type. In impulse stage type, pressure drop occurs only in nozzles and moving blades facilitates in changing the direction of fluid flow, thereby increasing the velocity of the flow and no pressure drop occurs in moving blades. In impulse-reaction stage type, pressure drop occurs in both nozzles and moving blades resulting in the generation of kinetic energy. In reaction stage type, flow enters the moving blades, changes its direction resulting in the increase of velocity and also undergoes a pressure drop. Generally speaking, reaction type stage is more efficient than impulse type stage due to less frictional losses, boundary layer separation losses, secondary flow losses and tip leakage losses. In impulse stage, nozzles are mounted in nozzle diaphragms and project inwards from the casing towards rotor and moving blades are mounted in rotor disc and project upwards from the rotor whereas in reaction stage, nozzles are mounted on guide blade carriers projecting inwards and moving blades are mounted on rotor projecting outwards such that the nozzles and moving blades are configured in opposite direction.

Figure 1 illustrates a sectional view of two adjacent moving blades depicting typical blade features.
The airfoil sections of two adjacent moving blades (10 and 12) is disclosed wherein the blades include a convex suction side (14 and 16), a concave pressure side (18 and 20), a leading edge (22 and 24) and a trailing edge (26 and 28).

The parameters which define the geometry and configuration of the moving blades in a row are as follows: The distance between trailing edges (26 and 28) of two adjacent blades (10 and 12) typically referred to as pitch is indicated by a letter ‘P1’. The axial length of the blade typically referred to as width is indicated by a letter ‘W1’. The inlet and exit blade angles are indicated by letters a1 and ß1 respectively. The shortest distance between trailing edge 26 of blade 10 to convex suction surface 16 of blade 12 typically referred to as throat is indicated by a letter ‘D1’. The angle between the chord line 21 and turbine axial direction (meridional direction) typically referred to as stagger angle is indicated by a letter ‘S1’.

Figure 2 illustrates sectional view of two adjacent nozzles depicting typical nozzle features.
The airfoil sections of two adjacent nozzles (30 and 32) is disclosed wherein the nozzles include a convex suction side (34 and 36), a concave pressure side (38 and 40), a leading edge (42 and 44) and a trailing edge (46 and 48).

The parameters which define the geometry and configuration of the nozzles in a stage are as follows: The distance between trailing edges (46 and 48) of two adjacent nozzles (30 and 32) typically referred to as pitch is indicated by a letter ‘P2’. The axial length of the nozzle typically referred to as width is indicated by a letter ‘W2’. The inlet and exit nozzle angles are indicated by letters a2 and ß2 respectively. The distance between trailing edge 46 of blade 30 to convex suction surface 36 of blade 32 typically referred to as throat is indicated by a letter ‘D2’. The angle between the chord line 41 and turbine axial direction (meridional direction) typically referred to as stagger angle is indicated by a letter ‘S2’.

Several techniques have been disclosed in the prior art illustrating the optimization of nozzle and blade profiles based on various parameters.

US Patent Publication No: 20080063530 published on March 13th, 2008 titled “HP Turbine Blade Airfoil Profile” discloses optimization of first stage blade in a two stage high pressure gas turbine to achieve maximum work, minimize secondary flow losses, flow separation losses and tip leakage losses.

US Patent No: 5277549 filed on March 16, 1992 titled “Controlled Reaction L-2R Steam Turbine” teaches about high performance tapered and twisted turbine blade deployed in low pressure module of a steam turbine to minimize energy loss through row of blades and control the radial distribution of degree of reaction.

Non Patent Literature published in Journal of Computational and Applied Mechanics, Vol.5., No.2., (2004), pp. 311-321 titled “Numerical optimization of a high pressure steam turbine stage” disclosed optimization of HP impulse stage of a 200 MW steam turbine having cylindrical stator blades and tapered and twisted rotor blades with an objective to minimize enthalpy loss of the stage. In this the blade profile hasn’t been changed but other parameters like stator and rotor blade numbers, stagger angles, rotor blade twist angle and stator blade compound lean at root and tip are optimized.

Generally, In prior art, optimization is done on blades for design requirements meeting design constraints considering minimum boundary layer separation losses, secondary flow losses, tip leakage losses etc., The blades thus developed operates at targeted efficiency at design conditions and operates at below the targeted efficiency at off design conditions (i.e., Mass flow varies). The primary design requirement herein is to develop a high pressure blade profile which can perform equally well on different megawatt range of steam turbines at different boundary conditions without compromising much on efficiency.

Therefore, there is a felt need for development of a high pressure blade profile to overcome the drawbacks of the prior art and thereby provide an efficient high pressure blade profile suitable for use in wide range of steam turbines.

OBJECTS OF THE INVENTION:
An object of the present invention is to provide a high pressure blade capable of working efficiently in wide megawatt range of steam turbines.

Another object of the present invention is to provide a high pressure blade capable of working efficiently at different boundary conditions.

One more object of the present invention is to provide a high pressure blade having no wake formation at trailing edge.

Still another object of the present invention is to provide advanced airfoil geometry for a high pressure blade to minimize frictional losses, boundary layer separation losses, secondary flow losses and tip leakage losses.

Further another object of the present invention is to provide a high pressure blade having flat efficiencies for different boundary conditions.

Yet one more object of the present invention is to reduce cost and time involved in development of a high pressure blade for different design requirements.

BRIEF DESCRIPTION OF THE DRAWINGS:
The invention will now be described with reference to the accompanying drawings in which:

Figure 1 illustrates a sectional view of two adjacent blades depicting typical blade features according to the prior art;

Figure 2 illustrates sectional view of two adjacent nozzles depicting typical nozzle features according to the prior art;

Figure 3(a) illustrates a top sectional view of analytical model of hypothetical high pressure blade base profile obtained according to predefined input and set of predefined constraints in accordance with the present invention;

Figure 3(b) illustrates a top sectional view of analytical model of hypothetical high pressure nozzle base profile obtained according to predefined input and set of predefined constraints in accordance with the present invention;

Figure 4(a) illustrates a plot showing curvature of high pressure blade base profile of figure 3(a);

Figure 4(b) illustrates a plot showing curvature of high pressure nozzle base profile of figure 3(b);

Figure 5 illustrates a plot of degree of reaction of high pressure module at hub, mean and tip of high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a) for a simulation run at predefined input and set of predefined constraints in accordance with the present invention;

Figure 6 illustrates a plot showing efficiencies across the stages of high pressure module using high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a) for a simulation run at predefined input and set of predefined constraints in accordance with the present invention;

Figure 7(a) illustrates a top sectional view of final model of refined high pressure blade profile achieved after aerodynamic and thermodynamic optimization in accordance with the present invention;

Figure 7(b) illustrates a top sectional view of final model of refined high pressure nozzle profile achieved after aerodynamic and thermodynamic optimization in accordance with the present invention;

Figure 8(a) illustrates a plot showing curvature of refined high pressure blade profile of figure 7(a);

Figure 8(b) illustrates a plot showing curvature of refined high pressure nozzle profile of figure 7(b);

Figure 9(a) illustrates an isometric view of high pressure blade of figure 7(a);

Figure 9(b) illustrates a front view of high pressure blade of figure 9(a);

Figure 9(c) illustrates a left side view of high pressure blade of figure 9(a);

Figure 9(d) illustrates a right side view of high pressure blade of figure 9(a);

Figure 9(e) illustrates a back view of high pressure blade of figure 9(a);

Figure 9(f) illustrates a top view of high pressure blade of figure 9(a);

Figure 10 illustrates an isometric view of high pressure nozzle of figure 7(b);

Figure 11 illustrates a plot of efficiency of a stage of high pressure module using refined high pressure nozzles and high pressure blades applied with boundary conditions of fifth stage of high pressure module of figure 6;

Figure 12 illustrates a plot of degree of reaction of high pressure module using refined high pressure nozzles and high pressure blades for a simulation run at different set of boundary conditions; and

Figure 13 illustrates a plot of efficiency of high pressure module using refined high pressure nozzles and high pressure blades for a simulation run at different set of boundary conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
Figure 3(a) illustrates a top sectional view of analytical model of hypothetical high pressure blade base profile obtained according to predefined input and set of predefined constraints.

Figure 3(b) illustrates a top sectional view of analytical model of hypothetical high pressure nozzle base profile obtained according to predefined input and set of predefined constraints.

In accordance with the present invention, the base profile is obtained initially by giving the predefined input and set of predefined constraints in the blade generating software (“Axial”). The predefined input and set of predefined constraints are governed by standard design rules employed in steam turbine industry.
Hypothetical operational input data and a set of predefined constraints are as follows:
1)Operational Input Data:
Inlet pressure 81.94 bar
Exit Pressure 60.02 bar
Inlet Temperature 504.90c
Mass flow 71.3 kg/sec
Speed of Rotor Drum (N)3000 rpm
Hub Radius 300 mm

2) Set of predefined constraints:
Achieve thermodynamic loading(delta h/U2)- (change in enthalpy/square of peripheral velocity of rotor) 1.2 to 1.45
Achieve Mean Reaction 45-55%
Optimum Peripheral velocity of rotor/Tangential velocity of steam flow (U/Cs) 0.6 to 0.7
Optimum Swirl 10 to 20 deg
Axial velocity of steam flow/peripheral velocity of the rotor (Ca/U) 0.2 to 0.35
Pitch/ Chord(At Hub) 0.88 to 0.97
Efficiency 90%

Figure 4(a) illustrates a plot showing curvature of high pressure blade base profile of figure 3(a).

Figure 4(b) illustrates a plot showing curvature of high pressure nozzle base profile of figure 3(b).
The x-axis in the figures 4(a) & 4(b) indicates axial length of high pressure blade base profile and high pressure nozzle base profile respectively. The y-axis in the figures 4(a) & 4(b) indicates variation in curvature of the profile of the high pressure blade and high pressure nozzle across the axial length respectively. The green legend in the figures 4(a) & 4(b) indicates suction side of the profile and the blue legend in the figures 4(a) & 4(b) indicates pressure side of the profile. A sudden change on the suction side of the profile (green legend) as shown in the figures 4(a) & 4(b) indicates that the profile is not a smooth curve.

Figure 5 illustrates a plot of degree of reaction of high pressure module at hub, mean and tip of high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a) for a simulation run at predefined input and set of predefined constraints.
By considering above mentioned operational input data and set of predefined constraints and based on pressure drop required, a simulation is run on seven stage high pressure module using high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a).
The height of the blades in each stage of seven stage high pressure module is determined by using formula above mentioned in formula section. The odd numbers on the x-axis of the plot represents nozzles and the even numbers on the x-axis of the plot represents blades. The y-axis of the plot represents percentage of reaction. The green legend, red legend and blue legend in the plot indicates the degree of reaction at hub, mean and tip of nozzles and blades. It is evident from the plot that the mean reaction (red legend) is within the constraint limits of 45% to 55%.

Figure 6 illustrates a plot showing efficiencies across the stages of high pressure module using high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a) for a simulation run at predefined input and set of predefined constraints.
A simulation is run on seven stage high pressure module using high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a) at above mentioned operational input data and set of predefined constraints and efficiency is plotted. The x-axis of the plot represents stages of high pressure module and y-axis of the plot represents efficiency. The blue legend in the plot represents total to total efficiency (dry efficiency) and the red legend in the plot represents total to static efficiency (wet efficiency). It can be observed from the plot that total to total efficiency of fifth stage of the high pressure module is 87.6%.

Figure 7(a) illustrates a top sectional view of final model of refined high pressure blade profile achieved after aerodynamic and thermodynamic optimization.

Figure 7(b) illustrates a top sectional view of final model of refined high pressure nozzle profile achieved after aerodynamic and thermodynamic optimization.
It can be observed from the figures 7(a) & 7(b) that the leading edge thickness of refined high pressure blade profile and refined high pressure nozzle profile has been increased considerably and the trailing edge thickness of refined high pressure blade profile and refined high pressure nozzle profile has been made sharp. It is evident that the shape of the final refined high pressure blade profile and final refined high pressure nozzle profile is same.

Figure 8(a) illustrates a plot showing curvature of refined high pressure blade profile of figure 7(a).

Figure 8(b) illustrates a plot showing curvature of refined high pressure nozzle profile of figure 7(b).
The x-axis in the figures 8(a) & 8(b) indicates axial length of refined high pressure blade profile and refined high pressure nozzle profile respectively. The y-axis in the figures 8(a) & 8(b) indicates variation in curvature of the profile of the high pressure blade and high pressure nozzle across the axial length respectively. The green legend in the figures 8(a) & 8(b) indicates suction side of the profile and the blue legend in the figures 8(a) & 8(b) indicates pressure side of the profile. The suction side of the profile (green legend) as shown in the figures 8(a) & 8(b) indicates that the profile is a smooth curve.

Figure 9(a) illustrates an isometric view of high pressure blade of figure 7(a).

Figure 9(b) illustrates a front view of high pressure blade of figure 9(a).

Figure 9(c) illustrates a left side view of high pressure blade of figure 9(a).

Figure 9(d) illustrates a right side view of high pressure blade of figure 9(a).

Figure 9(e) illustrates a back view of high pressure blade of figure 9(a).

Figure 9(f) illustrates a top view of high pressure blade of figure 9(a).
In accordance with the present invention, there is provided a high pressure blade 120 comprising a convex suction side 122, a concave pressure side 124, a leading edge 126 and a trailing edge 128.

Table 1 elucidates the geometry defining parameters at hub of high pressure blade 120 of figure 9(a). As the high pressure blade profile in question is of cylindrical blade, the geometry parameters will not be varying spanwise across Hub, Mean and Tip except parameters associated with radius from axis of rotor drum like pitch etc.

Table 1
Parameter Hub Section(H-H)
Chord 19.78 mm
Inlet Angle 11.68 deg
Exit Angle -72.8 deg
Leading edge radius 3 mm
Stagger Angle -38.66 deg
Trailing edge radius 0.098 mm
Unguided turning 14.56 deg
Angle of Attack -38.66 deg
Area 9.26 mm2
Axial chord(width) 14.18 mm
Camber 84.48 deg
Maximum Thickness 4.88 mm
Pitch/Chord 0.8214
Radius at CG 300 mm
Solidity 1.217
Throat/Pitch 0.2879
Tmax/Chord 0.2485

Figure 10 illustrates an isometric view of high pressure nozzle of figure 7(b).

In accordance with the present invention, there is provided a high pressure nozzle 140 comprising a convex suction side 142, a concave pressure side 144, a leading edge 146 and a trailing edge 148.

Table 2 elucidates the geometry defining parameters at hub of high pressure nozzle of figure 10.
Table 2
Parameter Hub Section(H-H)
Chord 19.78 mm
Inlet Angle - 11.68 deg
Exit Angle 72.8 deg
Leading edge radius 3 mm
Stagger Angle 38.66 deg
Trailing edge radius 0.098 mm
Unguided turning 14.56 deg
Angle of Attack 38.66 deg
Area 9.26 mm2
Axial chord(width) 14.18 mm
Camber -84.48 deg
Maximum Thickness 4.88 mm
Pitch/Chord 0.8214
Radius at CG 300 mm
Solidity 1.217
Throat/Pitch 0.2879
Tmax/Chord 0.2485

The aerofoil shape (geometry) is same for both high pressure blade 120 and high pressure nozzle 140. However, the high pressure blades 120 and high pressure nozzles 140 are configured in opposite direction by means of assembling T-root in the slot provided on the rotor drum. The claim of the application in question is only with respect to optimized profile shape of the high pressure blade 120 and high pressure nozzle 140.

TEST RESULTS:
Figure 11 illustrates a plot of efficiency of a stage of high pressure module using refined high pressure nozzles and high pressure blades applied with boundary conditions of fifth stage of high pressure module of figure 6.
Simulation is run on a stage of high pressure module using refined high pressure nozzles 140 and high pressure blades 120 applied with boundary conditions of fifth stage of high pressure module using high pressure nozzles of figure 3(b) and high pressure blades of figure 3(a).

The boundary conditions are applied as below and efficiency is plotted.
Inlet pressure 69.33 bar
Exit Pressure 66.02 bar
Inlet Temperature 478.70c
Mass flow 71.3 kg/sec
Speed of Rotor Drum (N) 3000 rpm
Hub Radius 300 mm

The x-axis of the plot represents a stage of high pressure module and y-axis of the plot represents efficiency. The blue legend in the plot represents total to total efficiency (dry efficiency) and the red legend in the plot represents total to static efficiency (wet efficiency). It can be observed from the plot that total to total efficiency of a stage of high pressure module is 88.6% which is 1% above the total to total efficiency of fifth stage of high pressure module of figure 6.

Figure 12 illustrates a plot of degree of reaction of high pressure module using refined high pressure nozzles and high pressure blades for a simulation run at different set of boundary conditions.

Figure 13 illustrates a plot of efficiency of high pressure module using refined high pressure nozzles and high pressure blades for a simulation run at different set of boundary conditions.

Simulation is run at different set of boundary conditions to monitor the performance of the refined high pressure nozzles 140 and high pressure blades 120. A five stage high pressure module using refined high pressure nozzles 140 and high pressure blades 120 is
considered and applied with following set of boundary conditions. The height of the blades in each stage of five stage high pressure module is determined by using formula above mentioned in formula section.

Operational Input Data:
Inlet pressure 25.25 bar
Exit Pressure 9.79 bar
Inlet Temperature 3430c
Mass flow 38.8 kg/sec
Speed of Rotor Drum (N)6150 rpm
Hub Radius 240 mm

Set of predefined constraints:
Achieve thermodynamic loading(delta h/U2)- (change in enthalpy/square of peripheral velocity of rotor) 1.2 to 1.45
Achieve Mean Reaction 45-55%
Optimum Peripheral velocity of rotor/Tangential velocity of steam flow (U/Cs) 0.6 to 0.7
Optimum Swirl 10 to 20 deg
Axial velocity of steam flow/peripheral velocity of the rotor (Ca/U) 0.2 to 0.35
Pitch/ Chord(At Hub) 0.88 to 0.97
Efficiency 90%

Referring to the figure 12, the odd numbers on the x-axis of the plot represents nozzles and the even numbers on the x-axis of the plot represents blades. The y-axis of the plot represents percentage of reaction. The green legend, red legend and blue legend in the plot indicates the degree of reaction at hub, mean and tip of nozzles and blades. It is evident from the plot that the mean reaction (red legend) is almost 50%.

Referring to the figure 13, the x-axis of the plot represents stages of five stage high pressure module and y-axis of the plot represents efficiency. The blue legend in the plot represents total to total efficiency (dry efficiency) and the red legend in the plot represents total to static efficiency (wet efficiency). It can be observed from the plot that total to total efficiency across the stages of five stage high pressure module is flat 90%.

The claim of the application in question is a high pressure blade profile geometry which can achieve flat efficiencies (88% to 90%) across different sets of boundary conditions applied in standard high pressure module range.

TECHNICAL ADVANCEMENTS:
A high pressure blade of a fluid flow machine has several technical advantages including but not limited to the realization of :
• a high pressure blade capable of working efficiently in wide megawatt range of steam turbines;
• a high pressure blade capable of working efficiently at different boundary conditions;
• a high pressure blade having no wake formation at trailing edge;
• an advanced airfoil geometry for a high pressure blade to minimize frictional losses, boundary layer separation losses, secondary flow losses and tip leakage losses;
• a high pressure blade having flat efficiencies for different boundary conditions; and
• reduction of cost and time involved in development of a high pressure blade for different design requirements.

Although the invention has been described herein above with reference to the embodiments of the invention, the invention is not limited to the embodiments described herein above. It is to be understood that modifications and variations of the embodiments can be made without departing from the spirit and scope of the invention.