US20020074102A1 - Method using secondary orientation to tune bucket natural frequency - Google Patents

Method using secondary orientation to tune bucket natural frequency Download PDF

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Publication number
US20020074102A1
US20020074102A1 US09/735,503 US73550300A US2002074102A1 US 20020074102 A1 US20020074102 A1 US 20020074102A1 US 73550300 A US73550300 A US 73550300A US 2002074102 A1 US2002074102 A1 US 2002074102A1
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United States
Prior art keywords
turbine bucket
tuning
frequencies
bucket
natural frequency
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
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US09/735,503
Inventor
John Wang
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General Electric Co
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General Electric Co
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Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to US09/735,503 priority Critical patent/US20020074102A1/en
Assigned to GENERAL ELECTRIC COMPANY reassignment GENERAL ELECTRIC COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: WANG, JOHN ZHIQIANG
Priority to EP01306925A priority patent/EP1217170A3/en
Priority to KR1020010048952A priority patent/KR20020046909A/en
Priority to CZ20012940A priority patent/CZ20012940A3/en
Priority to JP2001245829A priority patent/JP2002201902A/en
Assigned to ENERGY, UNITED STATES DEPARTMENT OF reassignment ENERGY, UNITED STATES DEPARTMENT OF CONFIRMATORY LICENSE (SEE DOCUMENT FOR DETAILS). Assignors: GENERAL ELECTRIC COMPANY
Publication of US20020074102A1 publication Critical patent/US20020074102A1/en
Abandoned legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D1/00—Non-positive-displacement machines or engines, e.g. steam turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/16—Form or construction for counteracting blade vibration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould
    • B22D27/045—Directionally solidified castings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/26—Antivibration means not restricted to blade form or construction or to blade-to-blade connections or to the use of particular materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2230/00—Manufacture
    • F05D2230/20—Manufacture essentially without removing material
    • F05D2230/21—Manufacture essentially without removing material by casting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2300/00—Materials; Properties thereof
    • F05D2300/60—Properties or characteristics given to material by treatment or manufacturing
    • F05D2300/607—Monocrystallinity

Definitions

  • This invention relates to gas turbine bucket construction and, more particularly, to using secondary orientation to tune turbine bucket natural frequencies.
  • the turbine blade or turbine bucket experiences different dynamic stimuli due to the aerodynamic disturbances from, for example, the up- and down-stream nozzles, the combustor cans, the tip shrouds, etc.
  • any of these stimulus frequencies is close enough to the natural frequency of the rotational turbine bucket, resonance may occur that will likely cause failures, usually catastrophic, to the bucket due to high cycle fatigue. Indeed, a large number of engine failures in the field can be traced back to the root cause of vibration related failures. Thus, it is important in bucket design to avoid resonance during operation by a sufficient margin.
  • a method of manufacturing a turbine bucket includes (a) investment casting the turbine bucket with a single crystal alloy, and (b) tuning a natural frequency of the turbine bucket without modifying physical features of the turbine bucket.
  • Step (b) may be practiced by tuning the natural frequency of the turbine bucket without affecting turbine bucket weight or turbine bucket shape.
  • Step (b) may also be practiced by tuning torsional and stripe mode frequencies without affecting flexure mode frequencies of the turbine bucket.
  • step (b) is preferably practiced by, prior to step (a), placing the crystal seed along a desired direction according to an orientation relative to the engine axial direction.
  • a method of tuning turbine bucket natural frequency includes (a) placing the crystal seed along a desired orientation relative to the engine axial direction, and (b) investment casting the turbine bucket with a single crystal alloy, wherein the desired orientation is selected to tune torsional frequencies without affecting flexure frequencies.
  • FIG. 1 illustrates a crystal orientation relative to engine orientations
  • FIG. 2 is a graph showing the effect of secondary orientation on 1T and 2T frequencies.
  • FIG. 3 is a graph showing the effect of secondary orientation on 1-2S and 1-3S frequencies.
  • the material directions along the X′ and Y′ axes are termed secondary orientation, while that along the Z′ direction is termed as the primary orientation.
  • the secondary orientation is defined by the angle ⁇ s between the engine axial direction X and the material direction X′, which is the same as the angle between the engine tangential direction Y and the material direction Y′.
  • Operating frequencies of turbine buckets can be determined in the design phase using engineering models and the like as would be apparent to those of ordinary skill in the art.
  • the data for FIGS. 2 and 3 is based on known Finite Element (FE) Analyses (known as ANSYS code) and is validated through engine tests. Similar engineering models by FE analyses can be used to determine bucket natural frequencies. As noted, it is important to avoid resonance by a sufficient margin to improve operating efficiency, and it thus may be necessary to “tune” the natural frequencies of a turbine bucket.
  • FE Finite Element
  • the shear modulus that determines the torsional frequencies is dependent on the secondary orientation ⁇ s .
  • the tensile modulus along the radial direction that determines the flexure frequencies is insensitive to the secondary orientation.
  • the secondary orientation can be used to tune the torsional frequencies without affecting the flexure frequencies.
  • FIG. 2 shows the change of 1T and 2T frequencies as a function of the secondary orientation.
  • FIG. 3 shows the change of 1-2S and 1-3S frequencies as a function of the secondary orientation. It is known that changes in the secondary orientation will not affect the flexure frequencies (such as 1F, 2F, etc.).
  • the change in secondary orientation does not entail changes in turbine bucket weight and shape. To implement certain preferred secondary orientation in an investment casting process is a relatively easy operation, thus the impact is minimal on manufacturing cost.
  • FIGS. 2 and 3 the data for FIGS. 2 and 3 is derived from FE analyses. First analyses are conducted by incorporating the secondary orientation in the engineering model, then the results are correlated with the engine test results. Subsequently, the secondary orientation is varied, and the curves are completed.
  • the secondary orientation is controlled by placing the crystal seed along a desired direction. Placing of the crystal seed in the investment casting process does not affect the physical features of the turbine bucket, such as the bucket weight or shape, and does not entail any additional manufacturing operation or cost. As shown in FIGS. 2 and 3, the desired direction of the crystal seed or secondary orientation is selected to effect a desired percentage change in turbine bucket natural frequencies.

Abstract

Tuning of turbine bucket torsional and stripe mode natural frequencies can be effected without altering any turbine bucket physical features, such as weight and/or shape, and without affecting flexure frequencies. The tuning of certain turbine bucket natural frequencies serves to avoid detrimental blade resonance, thus improving the reliability of a gas turbine. The method includes investment casting the turbine bucket with a single crystal alloy, and tuning the natural frequency of the turbine bucket without modifying physical features of the turbine bucket by placing a crystal seed along a desired direction according to a relative orientation of an engine axial direction.

Description

  • [0001] This invention was made with Government support under Contract No. DE-FC21-95MC-31176 awarded by the Department of Energy. The Government has certain rights in this invention.
    • BACKGROUND OF THE INVENTION
  • This invention relates to gas turbine bucket construction and, more particularly, to using secondary orientation to tune turbine bucket natural frequencies. [0002]
  • As a rotational component in a gas turbine engine, the turbine blade or turbine bucket experiences different dynamic stimuli due to the aerodynamic disturbances from, for example, the up- and down-stream nozzles, the combustor cans, the tip shrouds, etc. When any of these stimulus frequencies is close enough to the natural frequency of the rotational turbine bucket, resonance may occur that will likely cause failures, usually catastrophic, to the bucket due to high cycle fatigue. Indeed, a large number of engine failures in the field can be traced back to the root cause of vibration related failures. Thus, it is important in bucket design to avoid resonance during operation by a sufficient margin. [0003]
  • Previously, tuning of bucket natural frequencies has been accomplished using airfoil thickness to chord ratio, trailing edge wedge angle, trailing edge mass, airfoil wall thickness, cooling cavity size and number, tip shroud or cap, and camber. These previous methods, however, typically require the alteration of some physical feature of the bucket such as bucket weight or shape and/or increased production costs or altering the flex modes when only torsional or stripe modes are needed to be tuned. It is thus desirable to effect tuning of bucket torsional and stripe mode natural frequencies without altering any bucket physical features, without increasing bucket manufacturing cost, and without affecting the turbine bucket flexure frequencies. [0004]
    • BRIEF SUMMARY OF THE INVENTION
  • In an exemplary embodiment of the invention, a method of manufacturing a turbine bucket includes (a) investment casting the turbine bucket with a single crystal alloy, and (b) tuning a natural frequency of the turbine bucket without modifying physical features of the turbine bucket. Step (b) may be practiced by tuning the natural frequency of the turbine bucket without affecting turbine bucket weight or turbine bucket shape. Step (b) may also be practiced by tuning torsional and stripe mode frequencies without affecting flexure mode frequencies of the turbine bucket. In this context, step (b) is preferably practiced by, prior to step (a), placing the crystal seed along a desired direction according to an orientation relative to the engine axial direction. [0005]
  • In another exemplary embodiment of the invention, a method of tuning turbine bucket natural frequency includes (a) placing the crystal seed along a desired orientation relative to the engine axial direction, and (b) investment casting the turbine bucket with a single crystal alloy, wherein the desired orientation is selected to tune torsional frequencies without affecting flexure frequencies.[0006]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 illustrates a crystal orientation relative to engine orientations; [0007]
  • FIG. 2 is a graph showing the effect of secondary orientation on 1T and 2T frequencies; and [0008]
  • FIG. 3 is a graph showing the effect of secondary orientation on 1-2S and 1-3S frequencies. [0009]
    • DETAILED DESCRIPTION OF THE INVENTION
  • With reference to FIG. 1, in a single crystal alloy, the material directions along the X′ and Y′ axes are termed secondary orientation, while that along the Z′ direction is termed as the primary orientation. The secondary orientation is defined by the angle θ[0010] s between the engine axial direction X and the material direction X′, which is the same as the angle between the engine tangential direction Y and the material direction Y′.
  • Operating frequencies of turbine buckets can be determined in the design phase using engineering models and the like as would be apparent to those of ordinary skill in the art. The data for FIGS. 2 and 3 is based on known Finite Element (FE) Analyses (known as ANSYS code) and is validated through engine tests. Similar engineering models by FE analyses can be used to determine bucket natural frequencies. As noted, it is important to avoid resonance by a sufficient margin to improve operating efficiency, and it thus may be necessary to “tune” the natural frequencies of a turbine bucket. [0011]
  • In a bucket of single crystal alloy, the shear modulus that determines the torsional frequencies is dependent on the secondary orientation θ[0012] s. The tensile modulus along the radial direction that determines the flexure frequencies, on the other hand, is insensitive to the secondary orientation. Thus, with the method of the present invention, the secondary orientation can be used to tune the torsional frequencies without affecting the flexure frequencies. FIG. 2 shows the change of 1T and 2T frequencies as a function of the secondary orientation. FIG. 3 shows the change of 1-2S and 1-3S frequencies as a function of the secondary orientation. It is known that changes in the secondary orientation will not affect the flexure frequencies (such as 1F, 2F, etc.). Moreover, the change in secondary orientation does not entail changes in turbine bucket weight and shape. To implement certain preferred secondary orientation in an investment casting process is a relatively easy operation, thus the impact is minimal on manufacturing cost.
  • As noted, the data for FIGS. 2 and 3 is derived from FE analyses. First analyses are conducted by incorporating the secondary orientation in the engineering model, then the results are correlated with the engine test results. Subsequently, the secondary orientation is varied, and the curves are completed. [0013]
  • Investment casting with a single crystal alloy is known, and the details of the casting process will not be described herein. A related investment casting process is described in commonly-owned U.S. Pat. No. 5,713,722, the contents of which are herein incorporated by reference. [0014]
  • In the investment casting process, the secondary orientation is controlled by placing the crystal seed along a desired direction. Placing of the crystal seed in the investment casting process does not affect the physical features of the turbine bucket, such as the bucket weight or shape, and does not entail any additional manufacturing operation or cost. As shown in FIGS. 2 and 3, the desired direction of the crystal seed or secondary orientation is selected to effect a desired percentage change in turbine bucket natural frequencies. [0015]
  • While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. [0016]

Claims (8)

What is claimed is:
1. A method of manufacturing a turbine bucket comprising:
(a) investment casting the turbine bucket with a single crystal alloy; and
(b) tuning a natural frequency of the turbine bucket without modifying physical features of the turbine bucket.
2. A method according to claim 1, wherein step (b) is practiced by tuning the natural frequency of the turbine bucket without affecting turbine bucket weight.
3. A method according to claim 1, wherein step (b) is practiced by tuning the natural frequency of the turbine bucket without affecting turbine bucket shape.
4. A method according to claim 1, wherein step (b) is practiced by tuning torsional and stripe mode frequencies without affecting flexure mode frequencies of the turbine bucket.
5. A method according to claim 1, wherein step (b) is practiced by, prior to step (a), placing a crystal seed along a desired direction according to an orientation relative to an engine axial direction.
6. A method of tuning turbine bucket natural frequency comprising:
(a) placing a crystal seed along a desired orientation relative to an engine axial direction; and
(b) investment casting the turbine bucket with a single crystal alloy, wherein the desired orientation is selected to tune torsional frequencies without affecting flexure frequencies.
7. A method according to claim 6, comprising tuning the natural frequency of the turbine bucket without affecting turbine bucket weight.
8. A method according to claim 6, comprising tuning the natural frequency of the turbine bucket without affecting turbine bucket shape.
US09/735,503 2000-12-14 2000-12-14 Method using secondary orientation to tune bucket natural frequency Abandoned US20020074102A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US09/735,503 US20020074102A1 (en) 2000-12-14 2000-12-14 Method using secondary orientation to tune bucket natural frequency
EP01306925A EP1217170A3 (en) 2000-12-14 2001-08-14 Method to tune the natural frequency of turbine blades by using the orientation of the secondary axes
KR1020010048952A KR20020046909A (en) 2000-12-14 2001-08-14 Method using secondary orientation to tune bucket natural frequency
CZ20012940A CZ20012940A3 (en) 2000-12-14 2001-08-14 Method using secondary orientation to tune bucket natural frequency
JP2001245829A JP2002201902A (en) 2000-12-14 2001-08-14 Method using secondary azimuth for adjusting natural frequency of moving blade

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09/735,503 US20020074102A1 (en) 2000-12-14 2000-12-14 Method using secondary orientation to tune bucket natural frequency

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US20020074102A1 true US20020074102A1 (en) 2002-06-20

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EP (1) EP1217170A3 (en)
JP (1) JP2002201902A (en)
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CZ (1) CZ20012940A3 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050196268A1 (en) * 2004-03-02 2005-09-08 Shah Dilip M. High modulus metallic component for high vibratory operation
US20140072432A1 (en) * 2011-04-01 2014-03-13 Mtu Aero Engines Gmbh Blade arrangement for a turbo engine
DE102013226015A1 (en) * 2013-12-16 2015-07-16 MTU Aero Engines AG blade cascade
EP2444591A3 (en) * 2010-10-25 2015-11-25 United Technologies Corporation Turbine component and method for developing a component
EP2977553A1 (en) * 2014-07-22 2016-01-27 MTU Aero Engines GmbH Mistuned blade row for a turbomachine
CN109269745A (en) * 2018-10-30 2019-01-25 湖南科技大学 Large-scale bucket wheel machine cantilever low-frequency vibration test method based on carrying roller excitation method
US11499432B2 (en) * 2015-07-03 2022-11-15 Safran Aircraft Engines Method for altering the law of twist of the aerodynamic surface of a gas turbine engine fan blade
US11499431B2 (en) 2021-01-06 2022-11-15 General Electric Company Engine component with structural segment

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US20050227106A1 (en) * 2004-04-08 2005-10-13 Schlichting Kevin W Single crystal combustor panels having controlled crystallographic orientation
US7988412B2 (en) * 2007-08-24 2011-08-02 General Electric Company Structures for damping of turbine components
CN102451619B (en) * 2010-10-15 2013-11-20 中国石油化工股份有限公司 Y-shaped molecular sieve film and removal method for moisture in dichloromethane
DE102018202725A1 (en) 2018-02-22 2019-08-22 MTU Aero Engines AG Arrangement of blades in a blade ring based on a primary crystal orientation

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US3044746A (en) * 1960-05-18 1962-07-17 Gen Electric Fluid-flow machinery blading
US4605452A (en) * 1981-12-14 1986-08-12 United Technologies Corporation Single crystal articles having controlled secondary crystallographic orientation
US4804311A (en) * 1981-12-14 1989-02-14 United Technologies Corporation Transverse directional solidification of metal single crystal articles
US4919593A (en) * 1988-08-30 1990-04-24 Westinghouse Electric Corp. Retrofitted rotor blades for steam turbines and method of making the same
US5292385A (en) * 1991-12-18 1994-03-08 Alliedsignal Inc. Turbine rotor having improved rim durability
JPH0633701A (en) * 1992-07-16 1994-02-08 Hitachi Ltd Single crystal moving blade for gas turbine and production thereof
US5682747A (en) * 1996-04-10 1997-11-04 General Electric Company Gas turbine combustor heat shield of casted super alloy
JPH1136805A (en) * 1997-07-14 1999-02-09 Hitachi Ltd Turbine blade

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050196268A1 (en) * 2004-03-02 2005-09-08 Shah Dilip M. High modulus metallic component for high vibratory operation
US7338259B2 (en) 2004-03-02 2008-03-04 United Technologies Corporation High modulus metallic component for high vibratory operation
US20090297359A1 (en) * 2004-03-02 2009-12-03 Shah Dilip M High Modulus Metallic Component For High Vibratory Operation
US7871247B2 (en) 2004-03-02 2011-01-18 United Technologies Corporation High modulus metallic component for high vibratory operation
EP2444591A3 (en) * 2010-10-25 2015-11-25 United Technologies Corporation Turbine component and method for developing a component
US20140072432A1 (en) * 2011-04-01 2014-03-13 Mtu Aero Engines Gmbh Blade arrangement for a turbo engine
DE102013226015A1 (en) * 2013-12-16 2015-07-16 MTU Aero Engines AG blade cascade
US9765633B2 (en) 2013-12-16 2017-09-19 MTU Aero Engines AG Blade cascade
US9850766B2 (en) 2013-12-16 2017-12-26 MTU Aero Engines AG Blade cascade
EP2977553A1 (en) * 2014-07-22 2016-01-27 MTU Aero Engines GmbH Mistuned blade row for a turbomachine
DE102014214270A1 (en) * 2014-07-22 2016-02-18 MTU Aero Engines AG Bucket grid for a turbomachine
US9951623B2 (en) 2014-07-22 2018-04-24 MTU Aero Engines AG Blade cascade for a turbomachine
US11499432B2 (en) * 2015-07-03 2022-11-15 Safran Aircraft Engines Method for altering the law of twist of the aerodynamic surface of a gas turbine engine fan blade
CN109269745A (en) * 2018-10-30 2019-01-25 湖南科技大学 Large-scale bucket wheel machine cantilever low-frequency vibration test method based on carrying roller excitation method
US11499431B2 (en) 2021-01-06 2022-11-15 General Electric Company Engine component with structural segment

Also Published As

Publication number Publication date
KR20020046909A (en) 2002-06-21
EP1217170A3 (en) 2003-10-15
JP2002201902A (en) 2002-07-19
EP1217170A2 (en) 2002-06-26
CZ20012940A3 (en) 2002-07-17

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Effective date: 20010320

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STCB Information on status: application discontinuation

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