1. Fluid Force Identification
A method to Predict Wear of a Control Rod in a Nuclear Power Plant
Colloquim by J.W.M. De Jong
March
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2. Contents Introduction Research Objective Theory Practice Results
Conclusion
Contents
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3. Introduction Increasing demand for Nuclear Power
EDF operates 53 Nuclear Power Plants in France alone
Presurized Water Reactors vs Boiling Water Reactors
New design: European Pressurized Reactor (EPR)‏
Introduction
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4. Introduction
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5. Introduction
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6. Problem
The Spider with the Control Rods is extended from the Fuel Rod Assembly when in Operation
The Control Rods are Guided by Guide-plates
The Fluid Flow Induces a Vibration on the Control Rod
The Control Rods Wear out at the Guide-plates
Introduction
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7. Research Objective 'A Method to Model the Fluid Flow and to
Predict the Wear of the Control Rods'
Method is initiated by Bodel in 2008
My Task: To Verify and Validate this Method
Research Objective
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8. Comparison of Numerical Models
Static shapes as Expansion space
Mode-shapes in 2D
Different Mode-shapes to model system
Validation
Research Objective
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9. Theory
Modal Analysis
Fluid Force Modelling
Theory
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10. Modal Analysis
Theory
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11. Modal Analysis First Mode-shape f1 Frequency w1 = 2 [rad/s] Theory
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12. Modal Analysis Second Mode-shape f2 Frequency w2 = 4 [rad/s] Theory
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13. Modal Analysis Third Mode-shape f3 Frequency w3 = 6 [rad/s] Theory
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14. Modal Analysis
Theory
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15. Modal Analysis
Theory
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16. Modal Analysis
Theory
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17. Modelling the Fluid Force
Theory
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18. Modelling the Fluid Force
Theory
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19. Modelling the Fluid Force
Theory
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20. Modelling the Fluid Force
Theory
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21. Modelling the Fluid Force
Theory
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22. Theory
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23. Transfer Function
Theory
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24. The Method Model the System in Water using Mode-shapes...
...and use this System to calculate the Point Forces.
Theory
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25. The Study Practice Obtain Experimental Mode-shapes
Mass Normalize the Mode-shapes
Identify the Fluid Force
Practice
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26. Experimental Modal Analysis
Hammer excitation
Measure the input and output signal
Mass Normalize the Mode-shapes
Practice
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27. The Phacetie Model
Modelled
guide-plates
Practice
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28. Operational Modal Analysis
Strain gauges in-side the tube
Measure only the output signal
No Normalized Mode-shapes
Practice
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29. The Phacetie Model Practice Modelled guide-plates Water outlet nozzle
Water inlet nozzle
Practice
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30. Non-normalised Mode-shapes of the system in Water
Mass Normalised Mode-shapes of the system in Air
Frequency difference between Water and Air
Practice
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31. The Study Practice Obtain Experimental Mode-shapes
Mass Normalize the Mode-shapes
Identify the Fluid Force
Practice
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32. Assumptions wair > wwater = Modal mass
Mass Normalize the Mode-shapes
Practice
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33. Method I
For each mode
Practice
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34. The Study Practice Obtain Experimental Mode-shapes
Mass Normalize the Mode-shapes
Identify the Fluid Force
Practice
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35. Identifying the Forces
Identify the Point Forces by Inverting the Transfer Function using a Pseudo Inverse
Practice
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36. Results Method I Measured and Re-calculated
Modelling the system using the Mass normalised Mode-shapes in Water
Results
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37. Results Method I Calculated Point Forces
Modelling the system using the Mass normalised Mode-shapes in Water
Results
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38. Different mode-shapes to model system
Research Objective
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39. Modelling the System I Using the Mode-shapes obtained in Water
(Mass Normalised)‏ II
Using the Mode-shapes obtained in Air
(Re-normalised)‏
Practice
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40. Method I
For each mode
Practice
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41. Method II
For each mode
Practice
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42. Results Method II Measured and Re-calculated
Modelling the system using the re-normalised Mode-shapes in Air
Results
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43. Results Method II Calculated Point Forces
Modelling the system using the re-normalised Mode-shapes in Air
Results
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44. Conclusions
Use Mass Normalised Mode-shapes in water to describe the System
Conclusions
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45. Questions ?
Questions
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46. Conclusions
Experimental Mode-shapes obtained in Air are not Mass Normalised by the Measurement System
Transfering Identified Point Forces between different Models will not give the desired Result
Fundamental Problem with the Method: The measurment system uses a randomized signal if no input signal is measured.
Conclusions
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47. Extra
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48. Experimental Modal Analysis
Hammer excitation
Measure the input and output signal
Mass Normalize the Mode-shapes
Extra
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49. Operational Modal Analysis
Strain gauges in-side the tube
Measure only the output signal
No Normalized Mode-shapes
Extra
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50. The Numerical Models
The Study
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51. Extra
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52. The Study
Experimental
Numerical
The Study
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53. Assumptions
The mode-shapes are the same for the system in water and in air
(The Amplitudes of the modeshapes are not the same)‏
There is no added stiffness due to the water surrounding the tube.
The added mass due to the water surrounding the tube can be calculated from the frequency difference.
The Study
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54. Experimental
Numerical
The Study
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