Identifying bucket deformation in turbomachinery

Abstract

Embodiments of the present disclosure provide turbine buckets, turbomachinery, and related methods for identifying bucket deformation. A turbine bucket according to embodiments of the present disclosure can include an airfoil extending radially from a base, relative to a rotor axis of a turbomachine; and a magnetized material coupled to the airfoil proximal to a radially outer end thereof. To identify bucket deformation, a magnetic sensor can measure a magnetic field strength of the magnetized material, and a computing device in communication with the magnetic sensor can identify the turbine bucket as being one of deformed and non-deformed based on the magnetic field strength of the magnetized material.

What is claimed is: 
     
         1 . A turbine bucket comprising:
 an airfoil extending radially from a base, relative to a rotor axis of a turbomachine; and   a magnetized material coupled to the airfoil and proximal to a radially outer end thereof.   
     
     
         2 . The turbine bucket of  claim 1 , wherein the magnetized material comprises a magnetic braze alloy joined to the airfoil via one of a vacuum braze and a weld. 
     
     
         3 . The turbine bucket of  claim 1 , wherein the airfoil further includes a recess therein, wherein the magnetized material is housed within the recess. 
     
     
         4 . The turbine bucket of  claim 3 , wherein a surface of the magnetized material is substantially planar with an outer surface of the airfoil. 
     
     
         5 . The turbine bucket of  claim 1 , further comprising:
 a magnetic sensor configured to measure a magnetic field strength of the magnetized material; and   a computing device in communication with the magnetic sensor, wherein the computing device identifies the turbine bucket as being one of deformed and non-deformed based on the magnetic field strength of the magnetized material.   
     
     
         6 . The turbine bucket of  claim 5 , wherein the computing device is further configured to calculate a length of the turbine bucket based on the magnetic field strength of the magnetized material. 
     
     
         7 . The turbine bucket of  claim 5 , further comprising a shroud radially distal to the airfoil, wherein the magnetic sensor is coupled to the shroud. 
     
     
         8 . A turbomachine comprising:
 a rotor wheel coupled to a rotor;   a turbine bucket including:
 a base mechanically coupled to the rotor wheel, 
 an airfoil extending radially from the base, relative to a rotor axis of the turbomachine, wherein the airfoil includes a bucket tip proximal to a radially outer end thereof, and 
 a magnetized material coupled to the bucket tip; 
   a stationary component radially distal to the bucket tip; and   a magnetic sensor coupled to the stationary component, wherein the magnetic sensor measures a magnetic field strength of the magnetized material.   
     
     
         9 . The turbomachine of  claim 8 , further comprising a computing device in communication with the magnetic sensor, wherein the computing device identifies the turbine bucket as being one of deformed and non-deformed based on the magnetic field strength of the magnetized material. 
     
     
         10 . The turbomachine of  claim 8 , wherein the turbomachine comprises a gas turbine, and wherein the turbine bucket is positioned within a hot gas path (HGP) section of the gas turbine. 
     
     
         11 . The turbomachine of  claim 8 , wherein the computing device is further configured to calculate the length of the turbine bucket based on the magnetic field strength of the magnetized material. 
     
     
         12 . The turbomachine of  claim 8 , wherein the magnetized material comprises a magnetic braze alloy joined to the bucket tip via one of a vacuum braze and a weld. 
     
     
         13 . The turbomachine of  claim 8 , wherein the bucket tip further includes a recess therein, wherein the magnetized material is housed within the recess of the bucket tip. 
     
     
         14 . The turbomachine of  claim 13 , wherein the surface of the magnetized material is substantially planar with an outer surface of the bucket tip. 
     
     
         15 . A method for identifying bucket deformation in a turbomachine, the method comprising:
 measuring a magnetic field strength of a magnetized material positioned within a turbine bucket;   calculating a difference between the magnetic field strength and a reference field strength; and   identifying the turbine bucket as being one of deformed and non-deformed based on the calculated difference.   
     
     
         16 . The method of  claim 15 , further comprising calculating a length of the turbine bucket based on the magnetic field strength of the magnetized material. 
     
     
         17 . The method of  claim 15 , wherein the turbine bucket remains coupled to a rotor wheel of the turbomachine during the measuring. 
     
     
         18 . The method of  claim 15 , wherein the magnetized material comprises a magnetic braze alloy joined to the turbine bucket via one of a vacuum braze and a weld. 
     
     
         19 . The method of  claim 15 , further comprising, before the measuring:
 calibrating a position where a magnetic field strength of a magnetized material within a non-deformed turbine bucket is zero; and   setting the reference field strength as equal to zero at the calibrated position, wherein the measuring of the magnetic field strength occurs at the calibrated position.   
     
     
         20 . The method of  claim 15 , further comprising, before the measuring:
 forming a cavity in a bucket tip of the turbine bucket;   filling the cavity with the magnetized material; and   machining a surface of the magnetized material to be substantially planar with an outer surface of the bucket tip.