Spin Rig for NSMS Probe Development and Strain Gage Correlation

Transcription

1 Spin Rig for NSMS Probe Development and Strain Gage Correlation Terry Hayes, Bryan Hayes, Tom Tibbals, Steve Arnold Aerospace Testing Alliance (ATA) Arnold Air Force Base, TN Joel Davenport Univ. Of Tennessee Space Institute Tullahoma, TN 58 th International Instrumentation Symposium 3 rd Tip Timing Workshop San Diego, CA 5-6 June 2012 Air Force Materiel Command Arnold Engineering Development Center Arnold Air Force Base, TN

2 Standards Certification Education & Training Publishing Conferences & Exhibits AEDC Spin Rig for NSMS Probe Development and Strain Gage Correlation Terry Hayes, Bryan Hayes, Tom Tibbals, Steve Arnold Aerospace Testing Alliance (ATA) Arnold Air Force Base, TN Joel Davenport University of Tennessee Space Institute Tullahoma, TN

3 ARNOLD ENGINEERING DEVELOPMENT CENTER CONTRACTOR AEROSPACE TESTING ALLIANCE Ground Test Facility Diverse Test Units Aircraft System, Aeropropulsion, and Space and Missile Testing Government and Commercial customers Continuously Changing test objectives 3

4 Outline Introduction to NSMS Need for Probe Development Spin Rig AEDC Spin Rig Description AEDC Spin Rig Design AEDC Spin Rig Applications Probe Comparison Repeatability AEDC Spin Rig Improvement Areas Summary 4

5 Introduction to NSMS Non-contact Stress Measurement System Utilizes case mounted probes to measure blade tip deflection Measures blade tip deflection for all blades on a rotor Measurement is intrusive to the case but is non-contact to the blade Measures integral and non-integral vibrations plus static deflections Conversion from deflection to stress can be performed with a detailed Finite Element Model (FEM) of the blade 5

6 Introduction to NSMS NSMS Applications NSMS is primarily used as an analysis tool to acquire data for analysis of blade vibrations Provides blade vibration data like strain gages Amplitude, Frequency, Phase, Campbell Diagrams NSMS is secondarily used as a safety of test data system that is considered critical instrumentation NSMS has the advantage of obtaining data for every blade on a rotor which increases the chance of detecting an anomaly in the bladed rotor NSMS as a safety of test system has been utilized on more engine tests in recent months and seems to be gaining traction for future engine tests NSMS probes have a longer life span than strain gages and can be removed/repaired without engine rebuild 6

7 Need for Probe Development Spin Rig NSMS, as with any measurement system, must have quality sensors to provide quality data Probe Designs are driven by cost constraints and performance requirements (size, bandwidth, environment) Repeatable methods to quantify sensor performance are needed Method must be inexpensive but still provide realistic environment for probe comparisons 7

8 AEDC Spin Rig Description Objective The objective of the spin rig is to provide a smooth running rotor dynamics laboratory environment for NSMS software and hardware development without the safety and cost constraints of running an engine Provide inexpensive and rapid assessment Probe performance and check-out Probe comparison to a reference probe response NSMS SG correlation for deriving NSMS limits from SG component tests Tip deflection FEM model stress (could drive the FEM model with the tip deflections to establish limits) NSMS hardware validation and comparisons NSMS algorithm validation and comparisons 8

9 AEDC Spin Rig Description Rig originally part of a SpectraQuest Machinery Fault Simulator Rig provides a single shaft rotating system and motor with controller Rig has been highly modified (next slide) Rotating rig basic cost ~$6000 9

10 AEDC Spin Rig Design Main Rotor Drive Motor Exciter Motor (exciter rotor and concentric shaft removed) Main Rotor 10

11 AEDC Spin Rig Design Exciter rotor and concentric shaft installed 11

12 AEDC Spin Rig Design Able to adapt to NSMS needs without destroying fault simulator Handle 7 and 10.5 rotors Easy to align probes for either Leading RPM exciti Edge, N mag RPM rotori Trailing EO nat f exciti Slope 60 N Edge or Mid-chord probe locations mag Dual shaft for blade excitation control Excites +/- nodal diameters RPM excit f nat N mag RPM nat.lo RPM nat.hi max RPM excit RPM nat f excit Exciter control RPM showing constant excitation frequency RPM rotor At RPM rotor < RPM nat, RPM e xcit is counter-rotation to RPM rotor At RPM rotor > RPM nat, RPM e xcit is same direction as RPM rotor 12

13 AEDC Spin Rig Design Static Deflection Rotor 13

14 AEDC Spin Rig Design 36 Blade Rotor 36 Blade Rotor 10.5 Diameter 4 Blade Length.375 W x.100 T 1018 Carbon Steel FEA Frequencies (at 0 rpm) 1B: 200 Hz 2B: 1257 Hz 3B: 3520 Hz 1T: 4116 Hz 1B (axial): 752 Hz Stress/Deflection ratio: 261 psi/mil 14

15 Frequency (Hz) Frequency (Hz) AEDC Spin Rig Design Integral Excitation Example Strain Gage NSMS Rotor Speed Rotor Speed 36 Blade Rotor 7E Excitation with excitation rotor held fixed 15

16 Frequency (Hz) Frequency (Hz) AEDC Spin Rig Design NIV Excitation Example Strain Gage NSMS Rotor Speed Rotor Speed 36 Blade Rotor ~210 Hz NIV Excitation with excitation rotor being spun as function of main rotor speed to maintain constant excitation frequency 16

17 AEDC Spin Rig Applications Probe Comparison Using Static Deflection Rotor Optical Unfocused Spot Probe Comparison 5 µm transmit fiber 100 µm transmit fiber Multi-type Probe Comparison Optical Spot Optical Line Eddy Current Using 36 Blade Mistuned Rotor Optical Spot Eddy Current Repeatability Using 36 Blade Mistuned Rotor Using EDM Machined 36 Blade Rotor 17

18 Mils Mils Probe Comparison - Static Deflection Rotor 5 um vs. 100 um Spot Probe 120 Optical Spot Probe 5 um Blade Width 120 Optical Spot Probe 100 um Blade Width Blade 1 Blade 2 Blade 3 Blade 4 Blade 5 Blade 6 Blade 7 Blade 8 Blade 9 Blade 10 Blade 11 Blade 12 Blade 13 Blade 14 Blade 15 Blade Blade 1 Blade 2 Blade 3 Blade 4 Blade 5 Blade 6 Blade 7 Blade 8 Blade 9 Blade 10 Blade 11 Blade 12 Blade 13 Blade 14 Blade 15 Blade Rev Revs Revs Actual thickness: 126 mils 18

19 Mils Mils RPM Mils Mils RPM Mils Mils RPM Probe Comparison Static Deflection Rotor Blade Width Optical Spot Probe Blade Width Optical Line Probe Blade Width Revs Eddy Current Probe Blade Width Revs Revs Blade 1 Blade 2 Blade 3 Blade 4 Blade 5 Blade 6 Blade 7 Blade 8 Blade 9 Blade 10 Blade 11 Blade 12 Blade 13 Blade 14 Blade 15 Blade 16 RPM Blade 1 Blade 2 Blade 3 Blade 4 Blade 5 Blade 6 Blade 7 Blade 8 Blade 9 Blade 10 Blade 11 Blade 12 Blade 13 Blade 14 Blade 15 Blade 16 RPM Revs Revs Probe Comparison Blade 1 Blade 2 Blade 3 Blade 4 Blade 5 Blade 6 Blade 7 Blade 8 Blade 9 Blade 10 Blade 11 Blade 12 Blade 13 Blade 14 Blade 15 Blade 16 RPM True thickness 126 mils Speed Held to within 1% of target 19

20 Mils Mils Probe Comparison Static Deflection Rotor Blade Spacing Blade Spacing Actual spacing: 1374 mils Optical Spot Eddy Current Optical Line Blade # Blade # 20

21 Tip Deflection (mils p-p) Tip Deflection (mils p-p) Frequency (Hz) Frequency (Hz) Tip Deflection (mils p-p) Tip Deflection (mils p-p) Probe Comparison Mistuned Rotor Eddy Current vs. Optical Spot Blade # Blade # eddy optical eddy optical 100 Blade 23 Amplitude Tracking Rotor Speed Rotor Speed (RPM) eddy optical 21

22 Probe Development Spin Rig Repeatability To identify how well responses are consistent during separate test runs Temperature and Atmospheric Pressure noted Two rotors 36 Blade Mistuned Rotor 36 Blade EDM Machined Concentrated on the Mistuned rotor 22

23 Frequency (Hz) Repeatability 36 Blade Rotor Natural Frequencies Blade Natural Frequency - 1st Bend Blade # NSMS Blade # EDM Mistuned 23

24 Repeatability 36 Blade Rotor Mode Shapes 1B 2B

25 Repeatability Mistuned Rotor 7E/1B Blade Waterfall 25

26 Blade Tip Deflection (mils (mils p-p) p-p) Repeatability Mistuned Rotor 7E/1B Blade Tip Deflection 7E Excitation Disk Blade Number NSMS Blade # 3/ / / / / / / /

27 Frequency (Hz) Repeatability Mistuned Rotor 7E/1B Blade Frequency 7E Excitation Disk Blade Number NSMS Blade # 3/ / / / / / / /

28 Standard Deviation of Blade Tip Deflection (%) Repeatability Mistuned Rotor 7E/1B Blade Tip Deflection Standard Deviation 10 % % NSMS Blade # 28

29 Standard Deviation of Frequency (%) Repeatability Mistuned Rotor 7E/1B Blade Frequency Standard Deviation 1 % % NSMS Blade # 29

30 Repeatability Mistuned Rotor 1B NIV Blade Waterfall 30

31 Blade Tip Deflection Blade Tip (mils p-p) p-p) Repeatability Mistuned Rotor 1B NIV Blade Tip Deflection 7E Excitation Disk # NSMS Blade # 3/ / / / / /

32 Frequency (Hz) Repeatability Mistuned Rotor 1B NIV Blade Frequency 7E Excitation Disk # NSMS Blade # 3/ / / / / /

33 Standard Deviation of Blade Tip Deflection (%) Repeatability Mistuned Rotor 1B NIV Blade Tip Deflection Standard Deviation 25 % % NSMS Blade # 33

34 Standard Deviation of Frequency (%) Repeatability Mistuned Rotor 1B NIV Blade Frequency Standard Deviation 1 % % NSMS Blade # 34

35 Repeatability Mistuned Rotor NSMS Data with Strain Gage Data One channel telemetry system was installed on shaft to acquire a single channel of strain gage data on NSMS blade 18 Gage located 0.16 from blade root Stress/deflection ratio for the 1 st bending mode was determined by modeling and experimentally Model: 261 psi/mil Push Test: Blade 18: 155 psi/mil Blade 25: 224 psi/mil Blade 27: 272 psi/mil 35

36 Blade Tip Deflection Blade Tip (mils p-p) p-p) Repeatability Mistuned Rotor 7E/1B Blade Tip Deflection w/sg 7E Excitation Disk # NSMS Blade # nsms nsms nsms

37 Blade Stress (Ksi) (Ksi) Repeatability Mistuned Rotor 7E/1B Blade Stress w/sg 7E Excitation Disk # NSMS Blade # nsms nsms nsms sg sg sg

38 Blade Stress (Ksi) (Ksi) Repeatability Mistuned Rotor 7E/1B Blade Stress w/sg 7E Excitation Disk (zoomed) # NSMS Blade # nsms nsms nsms sg sg sg

39 Frequency (Hz) Repeatability Mistuned Rotor 7E/1B Blade Frequency w/sg 7E Excitation Disk # NSMS Blade # nsms nsms nsms sg sg sg RPM 39

40 Frequency Frequency (Hz) Repeatability Mistuned Rotor 7E/1B Blade Frequency w/sg 7E Excitation Disk (zoomed) # NSMS Blade # sg sg sg nsms nsms nsms RPM 40

41 Standard Deviation of Blade Stress (%) Repeatability Mistuned Rotor 7E/1B Blade Stress w/sg Standard Deviation % sg NSMS Blade # 41

42 Standard Deviation of Frequency (%) Repeatability Mistuned Rotor 7E/1B Blade Frequency w/sg Standard Deviation % sg NSMS Blade # 42

43 Blade Tip Deflection Blade Tip (mils p-p) p-p) Repeatability Mistuned Rotor 1B NIV Blade Tip Deflection w/sg 7E Excitation Disk # NSMS Blade # nsms nsms nsms

44 Blade Stress (Ksi) Blade Tip Deflection (mils p-p) Repeatability Mistuned Rotor 1B NIV Blade Stress w/sg 7E Excitation Disk # NSMS Blade # nsms nsms nsms sg sg sg

45 Blade Stress (Ksi) Blade Tip Deflection (mils p-p) Repeatability Mistuned Rotor 1B NIV Blade Stress w/sg 7E Excitation Disk (zoomed) # NSMS Blade # nsms nsms nsms sg sg sg

46 Frequency (Hz) Repeatability Mistuned Rotor 1B NIV Blade Frequency w/sg 7E Excitation Disk # NSMS Blade # nsms nsms nsms sg sg sg

47 Frequency (Hz) Repeatability Mistuned Rotor 1B NIV Blade Frequency w/sg 7E Excitation Disk (zoomed) # NSMS Blade # sg sg sg nsms nsms nsms

48 Standard Deviation of Blade Stress (%) Repeatability Mistuned Rotor 1B NIV Blade Stress w/sg Standard Deviation % sg NSMS Blade # 48

49 Standard Deviation of Frequency (%) Repeatability Mistuned Rotor 1B NIV Blade Frequency w/sg Standard Deviation % sg NSMS Blade # 49

50 Frequency (Hz) Blade Frequency (Hz) Repeatability 1B/7E Machined Rotor NSMS ACCEL #1 NSMS ACCEL #2 NSMS ACCEL #3 Modal Freq + Stiff Blade # NSMS Blade # 50

51 Tip Deflection (mils p-p) Mils Frequency FREQ RPM (Hz) Machined Rotor Other Responses 2B/16E and Axial 18ND B Peak_AMP Axial Peak_AMP 2B Frequency Axial Frequency Blade # NSMS Blade # 51

52 AEDC Spin Rig Improvement Areas Current motor and rotor system Motor is too slow (would like 10K RPM Motor is too small (larger rotor would increase tip velocities commensurate with modern fans) Cannot perform rapid transients (HP limited) Bearing problems (the main shaft ball pass frequency is noticeable in NSMS data; thrust bearings don t last long) Teardown for rotor changes is time consuming to get correct alignment Belt vibes are noticed in NSMS data Probes installation near base not possible Limits probe placement 52

53 Summary The AEDC Spin Rig has proven to be valuable for Integral and Non-integral excitation of rotor blades Probe Comparison Repeatability Testing The Spin Rig is somewhat limited to small, low speed applications due to its size A Second generation spin rig is needed to address current rig shortcomings 53

54 Conclusion Questions???? 54