Turbine airfoil clocking

In a turbine engine that includes as least five successive axially stacked rows of airfoils in one of a compressor and a turbine:

• a first airfoil row, a second airfoil row, a third airfoil row, a fourth airfoil row, and a fifth airfoil row;
• wherein the first airfoil row, the third airfoil row, and the fifth airfoil row each comprise one of a row of rotor blades and a row of stator blades, and the second airfoil row and the fourth airfoil row comprises the other;
• the method of establishing the circumferential position of the airfoils of the first airfoil row, the airfoils of the third airfoil row and the airfoils of the fifth airfoil row with respect each other, comprising:
• selecting an operating condition;
• determining at the operating condition the path of the wake flow from the trailing edge of the airfoils in the first airfoil row;
• determining at the operating condition the path of the wake flow as the wake flow enters and passes through the second airfoil row;
• determining at the operating condition the path of the wake flow from the second airfoil row to the location where the wake flow enters the third airfoil row;
• determining at the operating condition the path of the wake flow from the trailing edge of the airfoils in the third airfoil row;
• determining at the operating condition the path of the wake flow as the wake flow enters and passes through the fourth airfoil row;
• determining at the operating condition the path of the wake flow from the fourth airfoil row to the location where the wake flow enters the fifth airfoil row;
• locating at least a majority of the mid-channel points of the airfoils in the third airfoil row within +/−25% pitch of the third airfoil row with respect to the location at which the wake flow is determined to enter the third airfoil row;
• and
• locating at least a majority of the mid-channel points of the airfoils in the fifth airfoil row within +/−25% pitch of the fifth airfoil row with respect to the location at which the wake flow is determined to enter the fifth airfoil row;
• wherein:
• the first airfoil row comprises a row of compressor rotor blades in a fourteenth stage of the compressor;
• the second airfoil row comprises a row of compressor stator blades in the fourteenth stage of the compressor;
• the third airfoil row comprises a row of compressor rotor blades in a fifteenth stage of the compressor;
• the fourth airfoil row comprises a row of compressor stator blades in the fifteenth stage of the compressor;
• the fifth airfoil row comprises a row of compressor rotor blades in a sixteenth stage of the compressor;
• the row of rotor blades in the fourteenth stage comprises 64 rotor blades, the row of rotor blades in the fifteenth stage comprises 64 rotor blades, and the row of rotor blades in the sixteenth stage comprises 64 rotor blades;
• and
• the row of stator blades in the fourteenth stage comprises 132 stator blades, and the row of stator blades in the fifteenth stage comprises 130 stator blades.

In a turbine engine that includes at least three successive axially stacked rows of airfoils in one of a compressor and a turbine:

• a first airfoil row, a second airfoil row, and a third airfoil row;
• wherein the first airfoil row and the third airfoil row both comprise one of a row of rotor blades and a row of stator blades, and the second airfoil row comprises the other;
• the method of establishing the circumferential position of the airfoils of the third airfoil row with respect to the circumferential position blades of the first row of blades, comprising:
• selecting an operating condition;
• determining at the operating condition the path of the wake flow from the trailing edge of the airfoils in the first airfoil row;
• determining at the operating condition the path of the wake flow as the wake flow passes through the second airfoil row;
• determining at the operating condition the path of the wake flow from the second airfoil row to the location where the wake flow enters the third airfoil row;
• and
• locating at least a majority of the mid-channel points of the airfoils in the third airfoil row within +/−25% pitch of the third airfoil row with respect to the location at which the wake flow is determined to enter the third airfoil row;
• wherein:
• the first airfoil row comprises a row of compressor rotor blades in a fifteenth stage of the compressor;
• the second airfoil row comprises a row of compressor stator blades in the fifteenth stage of the compressor;
• and
• the third airfoil row comprises a row of compressor rotor blades in a sixteenth stage of the compressor;
• the row of rotor blades in the fifteenth stage comprises 64 rotor blades, and the row of rotor blades in the sixteenth stage comprises 64 rotor blades;
• and
• the row of stator blades in the fifteenth stage comprises 130 stator blades.