표제지

목차

Nomenclature 12

국문 요약 14

제1장 서론 16

1.1. 연구 배경 및 문헌조사 16

1.2. 연구 목적 20

제2장 스퀴즈 필름 댐퍼 개요 21

2.1. 스퀴즈 필름 댐퍼 소개 21

2.2. 스퀴즈 필름 댐퍼 구성 22

제3장 스퀴즈 필름 댐퍼 동적 평가 23

3.1. 스퀴즈 필름 댐퍼 시험 장치 소개 23

3.2. 스퀴즈 필름 댐퍼 시험 방법 및 절차 29

3.3. 임피던스 분해 결과 33

3.4. 열린 끝단 형태의 스퀴즈 필름 댐퍼 동특성 비교 38

3.4.1. SFD 공급 압력의 영향 38

3.4.2. SFD 공급 유량의 영향 39

3.4.3. SFD 윤활 틈새의 영향 40

3.4.4. SFD 축 방향 폭의 영향 41

3.4.5. SFD 저널 편심율의 영향 42

3.5. 피스톤 링 실 끝단 형태의 스퀴즈 필름 댐퍼 동특성 비교 43

3.5.1. SFD 공급 압력의 영향 43

3.5.2. SFD 공급 유량의 영향 44

3.5.3. SFD 윤활 틈새의 영향 45

3.5.4. SFD 축 방향 폭의 영향 46

3.5.5. SFD 저널 편심율의 영향 47

3.6. 엔드 플레이트 실 끝단 형태의 스퀴즈 필름 댐퍼 동특성 비교 48

3.6.1. SFD 공급 압력의 영향 48

3.6.2. SFD 공급 유량의 영향 49

3.6.3. SFD 저널 편심율의 영향 50

3.7. 세가지 끝단 형태의 스퀴즈 필름 댐퍼 동특성 비교 51

3.7.1. SFD 끝단 형상의 영향 51

제4장 스퀴즈 필름 댐퍼 동적 성능 예측 53

4.1. 스퀴즈 필름 댐퍼 모델링 53

4.2. 스퀴즈 필름 댐퍼 동적 성능 예측 결과 57

제5장 결론 59

참고문헌 61

ABSTRACT 64

부록 67

A. 스퀴즈 필름 댐퍼 모델링 검증 67

B. 충격시험: 시험 장치 고유진동수 파악 73

C. 동압 측정 및 압력장 해석 비교 77

Table 1. Normalized dimensions and lubricant properties of test SFD, test operating conditions 27

Table 2. Information and uncertainty of measurement sensors 28

Table A1. Reference geometry information and oil properties in open ends type SFD 67

Table A2. Reference geometry information and oil properties in piston ring seal ends type SFD 69

Table A3. Reference geometry information end plate seal ends type SFD 71

Figure 1. Schematic views of the squeeze film damper (a) Open ends (b) Sealed ends 21

Figure 2. Schematic views of the squeeze film damper (a) Open ends (b) Piston ring seal ends (c) End plate seal ends 22

Figure 3. Squeeze film damper test equipment configuration diagram (a) isometric photo (b) top view 23

Figure 4. Measuring sensor location and installation method of squeeze film damper test rig 24

Figure 5. Schematic diagram of lubricant supply and return system 25

Figure 6. Schematic view of the dynamic pressure sensor attachment location and lubricant flow in the test rig (a) top view (b) axial view 26

Figure 7. Squeeze film damper dynamic characteristics test method using test rig 29

Figure 8. Static load versus BC radial displacement and estimated structural stiffness at the 45° direction 30

Figure 9. Model of whirl orbit kinematics of force coefficients representing the actions of the squeeze film damper(SFD), support structure(s) and ends seal(seal) 31

Figure 10. Displacement, force, and acceleration data expressed in time and space for an SFDp with eccentricity=0.0, frequency=100 Hz, and dry condition (without oil) 33

Figure 11. Displacement, force, and acceleration data expressed in time and space for an SFDp with eccentricity=0.0, frequency=100 Hz, and wet condition (with oil) 34

Figure 12. Real and imaginary part impedance functions for SFDp with eccentricity ratio=0.0, dry condition(without oil) (a) direct average impedances (b) cross-coupled... 35

Figure 13. Real and imaginary part impedance functions for SFDp with eccentricity ratio=0.0, wet condition(with oil) (a) direct average impedances (b) cross-coupled... 36

Figure 14. Imaginary part of impedance versus frequency when oil supply pressure is constant at 2 barG in three end types of squeeze film dampers (SFDo, SFDp, SFDe) 37

Figure 15. Excitation frequency versus normalized average damping coefficients in supply pressure change of SFDo 38

Figure 16. Excitation frequency versus normalized average damping coefficients in supply flow rate change of SFDo 39

Figure 17. Excitation frequency versus normalized average damping coefficients due to changes in the lubrication clearance of SFDo 40

Figure 18. Excitation frequency versus normalized average damping coefficients due to axial width length variation of SFDo 41

Figure 19. Excitation frequency versus normalized average damping coefficients due to change in journal eccentricity ratio of SFDo 42

Figure 20. Excitation frequency versus normalized average damping coefficients in supply pressure change of SFDp 43

Figure 21. Excitation frequency versus normalized average damping coefficients in supply flow rate change of SFDp 44

Figure 22. Excitation frequency versus normalized average damping coefficients due to changes in the lubrication clearance of SFDp 45

Figure 23. Excitation frequency versus normalized average damping coefficients due to axial width length variation of SFDp 46

Figure 24. Excitation frequency versus normalized average damping coefficient due to change in journal eccentricity ratio of SFDp 47

Figure 25. Excitation frequency versus normalized average damping coefficients in supply pressure change of SFDe 48

Figure 26. Excitation frequency versus normalized average damping coefficients in supply flow rate change of SFDe 49

Figure 27. Excitation frequency versus normalized average damping coefficient due to change in journal eccentricity ratio of SFDe 50

Figure 28. Excitation frequency versus normalized average damping coefficient for journal eccentricity ratio and three ends shape (SFDo, SFDp, SFDe) 52

Figure 29. Mathematical modeling schematic view for developing a numerical analysis program for squeeze film dampers 53

Figure 30. Cross-sectional schematic view of SFD cartridge-journal according to three ends shape 56

Figure 31. Comparison of test results and KMU analysis results for eccentricity ratio at three end shapes (a)SFDo (b)SFDp (c)SFDe 58

Figure A1. Comparison of static eccentricity versus damping coefficient results to references test results and KMU prediction results in SFDo 68

Figure A2. Comparison of static eccentricity versus damping coefficient results to references test results and KMU prediction results in SFDp 70

Figure A3. Seal gap versus normalized attenuation coefficient for reference and KMU prediction results (a) LS＝25mm, (b) LS＝40mm[이미지참조] 72

Figure B1. Impact test to determine the natural frequency prior to tuning of the test rig. (a) Accelerometer attachment and impact location on the test rig (b) Frequency... 73

Figure B2. Impact test to determine the natural frequency after tuning of the test rig. (a) Accelerometer attachment and impact location on the test rig (b) Frequency... 74

Figure B3. Natural frequency of the stinger. (a) Accelerometer attachment and impact location on the test rig (b) Frequency versus FRF magnitude and phase 75

Figure B4. Natural frequency of the static loader. (a) Accelerometer attachment and impact location on the test rig (b) Frequency versus FRF magnitude and phase 76

Figure C1. Dynamic pressure and dimensionless film thickness (h/c) versus time. Test with circular centered (ε＝0.0) orbit amplitude r/c＝0.2 at a whirl frequency of 200 Hz.... 77