Turbomachine airfoil erosion determination

Abstract

A system may include at least one computer device configured to attain a two-dimensional used profile of a leading edge at a specified radial position on a turbomachine airfoil after use. The system aligns opposing substantially straight alignment portions of the two-dimensional used profile with opposing substantially straight alignment portions of a previously attained, two-dimensional, baseline profile of the turbomachine airfoil. The alignment portions of each profile are in substantially identical radial locations of the turbomachine airfoil. Comparing the used profile to the baseline profile determines whether the leading edge at the specified radial position of the used turbomachine airfoil has erosion. The system may also include a laser profiler for measuring the turbomachine airfoil.

What is claimed is: 
     
         1 . A system comprising:
 at least one computer device configured to perform the steps of:   attaining a two-dimensional used profile of a leading edge at a specified radial position on a turbomachine airfoil after use;   aligning opposing substantially straight alignment portions of the two-dimensional used profile with opposing substantially straight alignment portions of a previously attained two-dimensional, baseline profile of the turbomachine airfoil, the alignment portions of each profile being in substantially identical radial locations of the turbomachine airfoil; and   comparing the used profile to the baseline profile to determine whether the leading edge at the specified radial position of the used turbomachine airfoil has erosion.   
     
     
         2 . The system of  claim 1 , wherein the at least one computer device is configured to perform attaining the baseline profile, including:
 receiving a raw baseline profile of the leading edge of the turbomachine airfoil as measured by a profiler;   normalizing the raw baseline profile to attain the baseline profile by:
 identifying opposing substantially straight alignment portions of the raw baseline profile at a specified depth range from the leading edge of the raw baseline profile; 
 determining a compare angle of each opposing alignment portion relative to an axis centered at the leading edge of the raw baseline profile, and extending each alignment portion past the leading edge to identify an intersection point; and 
 attaining the baseline profile by translating the raw baseline profile to place the intersection point on the axis and rotating the raw baseline profile to make the compare angles of each alignment portion equal relative to the axis. 
   
     
     
         3 . The system of  claim 2 , wherein the attaining of the used profile includes:
 receiving a raw, two-dimensional used profile of the leading edge at the specified radial position on the turbomachine airfoil after use;   identifying the opposing substantially straight alignment portions of the raw used profile by performing a linear regression; and   attaining the used profile by performing any translating and rotating of the raw used profile necessary to allow aligning of the opposing substantially straight alignment portions of the raw used profile with the opposing substantially straight alignment portions of the baseline profile.   
     
     
         4 . The system of  claim 2 , wherein the raw baseline profile of the leading edge of the turbomachine airfoil is measured by a profiler prior to use of the turbomachine airfoil. 
     
     
         5 . The system of  claim 1 , wherein the attaining includes attaining a plurality of two-dimensional used profiles of the leading edge at a plurality of specified radial positions on the turbomachine airfoil; and
 the at least one computer device is further configured to perform the steps of: aligning and comparing each two-dimensional used profile to a previously attained, two-dimensional, baseline profile of the leading edge at a respective specified radial position on the turbomachine airfoil to determine whether the leading edge at the respective specified radial position has erosion.   
     
     
         6 . The system of  claim 1 , wherein the attaining includes attaining a two-dimensional used profile of a leading edge at a specified radial position on a plurality of circumferentially adjacent turbomachine airfoils after use; and
 the at least one computer device is further configured to perform the steps of:   aligning and comparing each two-dimensional used profile to a previously attained two-dimensional, baseline profile of the leading edge at the specified radial position of a respective turbomachine airfoil to determine whether the leading edge at the specified radial position of each turbomachine airfoil has erosion.   
     
     
         7 . The system of  claim 6 , wherein the at least one computer device is further configured to performs the steps of determining a trend in the two-dimensional used profiles of the plurality of turbomachine airfoils, and predicting a need for replacement or repair of at least one turbomachine airfoil. 
     
     
         8 . The system of  claim 1 , further comprising a laser profiler for measuring, during a point of non-use of the turbomachine airfoil, the two-dimensional used profile of the leading edge at the specified radial position on the turbomachine airfoil. 
     
     
         9 . The system of  claim 8 , further comprising a mount for mounting the laser profiler for measuring of the two-dimensional profile at the specified radial position. 
     
     
         10 . The system of  claim 9 , wherein the mount includes:
 a base configured to interact with at least one of: a rotor wheel, a shank of the turbomachine airfoil and an airfoil portion of the turbomachine airfoil,   a support for supporting the laser profiler, and   an elongated member for positioning the support relative to the base such that the laser profiler senses at the specified radial position.   
     
     
         11 . A computer-implemented method comprising:
 attaining a two-dimensional used profile of a leading edge at a specified radial position on a turbomachine airfoil after use;   aligning opposing substantially straight alignment portions of the two-dimensional used profile with opposing substantially straight alignment portions of a previously attained, two-dimensional, baseline profile of the turbomachine airfoil, the alignment portions of each profile being in substantially identical radial locations of the turbomachine airfoil; and   comparing the used profile to the baseline profile to determine whether the leading edge at the specified radial position of the used turbomachine airfoil has erosion.   
     
     
         12 . The method of  claim 11 , further comprising attaining the baseline profile, including:
 receiving a raw baseline profile of the leading edge of the turbomachine airfoil as measured by a profiler;   normalizing the raw baseline profile to attain the baseline profile by:
 identifying opposing substantially straight alignment portions of the raw baseline profile at a specified depth range from the leading edge of the raw baseline profile; 
 determining a compare angle of each opposing alignment portion relative to an axis centered at the leading edge of the raw baseline profile, and extending each alignment portion past the leading edge to identify an intersection point; and 
 attaining the baseline profile by translating the raw baseline profile to place the intersection point on the axis and rotating the raw baseline profile to make the compare angles of each alignment portion equal relative to the axis. 
   
     
     
         13 . The method of  claim 12 , wherein the raw baseline profile of the leading edge of the turbomachine airfoil is measured by a profiler prior to use of the turbomachine airfoil. 
     
     
         14 . The method of  claim 12 , wherein the attaining the used profile includes:
 receiving a raw, two-dimensional used profile of the leading edge at the specified radial position on the turbomachine airfoil after use;   identifying the opposing substantially straight alignment portions of the raw used profile by performing a linear regression; and   attaining the used profile by performing any translating and rotating of the raw used profile necessary to allow aligning of the opposing substantially straight alignment portions of the used profile with the opposing substantially straight alignment portions of the baseline profile.   
     
     
         15 . The method of  claim 11 , further comprising repeating the attaining, aligning and comparing for a plurality of radial positions on the leading edge of the turbomachine airfoil. 
     
     
         16 . The method of  claim 11 , further comprising repeating the attaining, aligning and comparing for a plurality of turbomachine airfoils of a particular stage of the turbomachine. 
     
     
         17 . The method of  claim 16 , further comprising determining a trend in the two-dimensional used profiles of the plurality of turbomachine airfoils, and using the trend to predict a need for replacement or repair of the turbomachine airfoil. 
     
     
         18 . The method of  claim 11 , further comprising repeating the attaining, aligning and comparing for the turbomachine airfoil over a period of usage of the turbomachine airfoil. 
     
     
         19 . The method of  claim 11 , further comprising mounting a laser profiler for measuring of the two-dimensional used profile at the specified radial position using a mount configured to ensure the laser profiler senses at the specified radial position. 
     
     
         20 . A program product stored on a computer readable medium for determining erosion of a turbomachine airfoil, the computer readable medium comprising program code for performing the following steps:
 attaining a two-dimensional used profile of a leading edge at a specified radial position on a turbomachine airfoil after use;   aligning opposing substantially straight alignment portions of the two-dimensional used profile with opposing substantially straight alignment portions of a previously attained, two-dimensional, baseline profile of the turbomachine airfoil, the alignment portions of each profile being in substantially identical radial locations of the turbomachine airfoil; and   comparing the used profile to the baseline profile to determine whether the leading edge at the specified radial position of the used turbomachine airfoil has erosion.