Patent Application
20110150659
The present disclosure relates generally to gas turbine compressor airfoils and more particularly to airfoil profiles for second stage compressor blades.
There are many design requirements for each stage of a gas turbine compressor in order for the stages to meet design goals including overall efficiency, airfoil loading and mechanical integrity. Of particular concern are the design of the second stage blade of a compressor, since it is an entry blade into the compressor.
Many airfoil profiles for gas turbines have been provided. See, for example EP0 887 513 B1, which discloses the stagger angle and camber angle of an airfoil of a first stage turbine blade. Compressor design is, however, at a constant state of flux due to a desire to improve efficiency. There is therefore an advantage in providing airfoil designs that improve the balance of mechanical integrity and aerodynamic efficiency in these newly developed turbines. There is therefore a desire to achieve airfoil designs to facilitate this development.
An exemplary embodiment provides airfoil for a second stage compressor blade. The exemplary airfoil comprises a plurality of chord lengths, a plurality of stagger angles, and a plurality of camber angles at a plurality of divisions, respectively, along an airfoil height starting from a reference point at a first end of the airfoil extending to a second distal end. At a first division starting from the reference point, the airfoil height is 0.000 mm, the stagger angle is 27.282 degrees, the chord length is 168.800 mm, and the chamber angle is 28.038 degrees. At a second division between the first division and the second distal end of the airfoil, the airfoil height is 63.053, the stagger angle is 33.687 degrees, the chord length is 168.600 mm, and the chamber angle is 24.400 degrees. At a third division between the second division and the second distal end of the airfoil, the airfoil height is 123.015 mm, the stagger angle is 39.234 degrees, the chord length is 169.600 mm, and the camber angle is 21.195 degrees. At a fourth division between the third division and the second distal end of the airfoil, the airfoil height is 180.479 mm, the stagger angle is 44.049 degrees, the chord length is 171.400 mm, and the camber angle is 18.324 degrees. At a fifth division between the fourth division and the second distal end of the airfoil, the airfoil height is 235.744 mm, the stagger angle is 48.213 degrees, the chord length is 173.500 mm, and the camber angle is 15.840 degrees. At a sixth division between the fifth division and the second distal end of the airfoil, the airfoil height is 289.030 mm, the stagger angle is 51.793 degrees, the chord length is 175.500 mm, and the camber angle is 13.693 degrees. At a seventh division between the sixth division and the second distal end of the airfoil, the airfoil height is 340.550 mm, the stagger angle is 54.848 degrees, the chord length is 177.100 mm, and the camber angle is 11.851 degrees. At an eighth division between the seventh division and the second distal end of the airfoil, the airfoil height is 390.500 mm, the stagger angle is 57.428 degrees, the chord length is 178.100 mm, and the camber angle is 10.289 degrees. At a ninth division between the eighth division and the second distal end of the airfoil, the airfoil height is 439.080 mm, the stagger angle is 59.577 degrees, the chord length is 178.000 mm, and the camber angle is 8.976 degrees.
Additional refinements, advantages and features of the present disclosure are described in more detail below with reference to exemplary embodiments illustrated in the drawings, in which:
Exemplary embodiments of the present disclosure provide an improved airfoil having a unique profile for improved performance of a gas turbine compressor. This is accomplished by a unique airfoil profile defined in terms of stagger angle and camber angle. Further, to reduce the weight of the airfoil, a reduced chord length is provided as compared to known airfoils.
According to an exemplary embodiment, the airfoil height can be scaled down by a factor of 1:1.2. In this way, unscaled and scaled aspects provide airfoils which are suitable for operation at nominally 50 Hz and 60 Hz, respectively.
Other objectives and advantages of the present disclosure will become apparent from the following description, taken in connection with the accompanying drawings which, by way of example, illustrate exemplary embodiments of the present disclosure.
Exemplary embodiments of the present disclosure are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. However, the present disclosure may be practiced without these specific details, and the present disclosure is not limited to the exemplary embodiments disclosed herein.
The stagger angle γ is defined, as shown in
The camber angle Δβ, as shown in
the outlet angle β2m, which is the angle, at the trailing edge TE, between the line PA perpendicular to the longitudinal axis LA and a tangent to the camber line CL. As shown in
As shown in
The stagger angle γ, camber angle Δβ and chord length CD, as defined in
An embodiment of the disclosure will now be described, by way of example, with reference to the dimensional characteristics defined in
In a further embodiment, the airfoil height AH is scaled down by a factor of 1:1.2 in order to be made suitable for operation at 60 Hz.
Although the disclosure has been herein shown and described in what is conceived to be an exemplary embodiment, it will be appreciated by those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the disclosure is indicated by the appended claims rather that the foregoing description and all changes that come within the meaning and range and equivalences thereof are intended to be embraced therein.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.
