표제지
요약
목차
1. 서론 15
1.1. 연구 배경 15
1.2. 선행 연구 18
1.2.1. 에너지 절감 장치(Energy Saving Device) 18
1.2.2. 제트 분사 장치 19
1.3. 연구 목적 및 내용 22
2. 이론 24
2.1. 스크류 프로펠러 24
2.2. 프로펠러 단독 시험 29
2.3. 캐비테이션 32
3. 모형실험 34
3.1. 제트 분사 프로펠러 설계 34
3.2. 실험 장비 설계 38
3.3. 사전 수치해석 40
3.3.1. 사전 수치해석 모델링 40
3.3.2. 사전 수치해석 결과 41
3.4. 실험 장비 제작 45
3.5. Calibration 46
3.5.1. 추력 & 토오크 46
3.5.2. 질량 유량 47
3.6. 모형실험 조건 49
3.7. 모형실험 결과 51
4. 수치해석 52
4.1. 수치해석 기법 52
4.1.1. 지배방정식 52
4.1.2. 난류모델 54
4.1.3. 경계조건 및 격자계 56
4.1.4. Grid dependency test 57
4.2. 모형실험 결과와의 비교 61
4.3. 프로펠러 효율 향상 가능성 검토 69
4.3.1. 분사량 및 슬릿 높이에 따른 성능 변화 69
4.3.2. 일반 프로펠러와의 비교 (t/c=0.24) 83
4.3.3. 일반 프로펠러와의 비교 (t/c=0.12) 88
4.4. 제트 분사 영역 형상 설계 93
4.5. 분사구 형상에 따른 성능 변화 97
4.5.1. 덮개 길이(lCO.)[이미지참조] 97
4.5.2. 슬릿 위치(pS)[이미지참조] 102
4.5.3. 슬릿 높이(hS)[이미지참조] 108
4.5.4. 슬릿-터널 면적 비율(AS/AT)[이미지참조] 119
4.5.5. 분사 범위 129
4.6. 분사구 형상 최적화 139
4.7. 피치(Pitch)에 따른 성능 변화 143
5. 결론 152
참고문헌 157
Table 1. Parameters of the Coanda propeller used in the experiment 36
Table 2. Comparison of mean velocity in each hole according to rotation 44
Table 3. Experimental conditions 50
Table 4. Parameters used for GCI calculation of thrust and torque in fine grid system 59
Table 5. Computation conditions according to the slit height 70
Table 6. The comparison of propeller performance change according to Cj at each slit height[이미지참조] 82
Table 7. Performance comparison of Coanda propeller with matched thrust of normal propeller (NACA66 (MOD, t/c=0.24)) 85
Table 8. Performance comparison of Coanda propeller with matched thrust of normal propeller (NACA66 (MOD, t/c=0.12)) 90
Table 9. Computation conditions and propeller performance comparison for each case 95
Table 10. Computation conditions and propeller performance comparison for each cover length 98
Table 11. Computation conditions and required power for pump according to the slit position 103
Table 12. Computation conditions and required power for pump according to the slit height 111
Table 13. Computation conditions and required power for pump according to the slit-tunnel area ratio 121
Table 14. Computation conditions and required power for pump according to the injection range 131
Table 15. Optimized slit shape specifications 140
Table 16. Performance comparison of optimized propeller with matched thrust of normal and previous propeller (NACA66 (MOD, t/c=0.12)) 142
Table 17. Computation conditions according to the pitch distribution with matching thrust 146
Figure 1. Global temperature compared to average 16
Figure 2. General definition of airfoil section 24
Figure 3. General definition of propeller geometry 25
Figure 4. Typical velocity diagram for a propeller blade section at radius r 28
Figure 5. Experimental equipment of propeller open water test 29
Figure 6. Different types of propeller cavitation 32
Figure 7. NACA66 (MOD) geometry of with jet and without jet 35
Figure 8. Propeller shape used in experiment 36
Figure 9. Name for each part of Coanda propeller 37
Figure 10. Diagram of the experimental setup 38
Figure 11. Chamber geometry of prior computations 40
Figure 12. Grid on the chamber and interface to rotate 41
Figure 13. Comparison of pressure inside the chamber according to rotation 42
Figure 14. Comparison of mean velocity distribution with or without rotation 43
Figure 15. Experimental Setup 45
Figure 16. Calibration result with oil seal attached 46
Figure 17. Acrylic box for mass flow calibration 47
Figure 18. Mass flow calibration according to propeller RPM(Rotate Per Minute) 48
Figure 19. Propeller performance change according to each Cj[이미지참조] 51
Figure 20. Computation domain and boundary conditions 56
Figure 21. Grid system for numerical simulations 57
Figure 22. Propeller open water test results of experiments and calculations 62
Figure 23. Schematic diagram of thrust PUA and torque PUA 63
Figure 24. Thrust PUA distribution on the propeller surface with and without jet injection (JA=0.4)[이미지참조] 65
Figure 25. Torque PUA distribution on the propeller surface with and without jet injection (JA=0.4)[이미지참조] 65
Figure 26. Tangential velocity distribution at the center of the slit (JA=0.4)[이미지참조] 66
Figure 27. Tangential velocity distribution according to with and without jet injection (r/R=0.73) 67
Figure 28. NACA66 (MOD, t/c=0.24) geometry for each slit height 69
Figure 29. KT according to Cj for each part of the propeller with each slit height (JA = 0.4)[이미지참조] 71
Figure 30. Distribution of tangential velocity and thrust PUA according to Cj for each slit height (JA = 0.4)[이미지참조] 73
Figure 31. Tangential velocity distribution at the center of the slit according to Cj for each slit height[이미지참조] 75
Figure 32. 10KQ according to Cj for each part of the propeller with each slit height (JA = 0.4)[이미지참조] 76
Figure 33. Distribution of torque PUA according to Cj for each slit height (JA = 0.4)[이미지참조] 77
Figure 34. Torque PUA distribution of inner structure at Cj=0.125[이미지참조] 79
Figure 35. Comparison of shapes of Coanda propellers and normal propeller 83
Figure 36. Hydrodynamic force on the surface of a Coanda propellers and normal propeller with matched thrust (NACA66 (MOD, t/c = 0.24)) 87
Figure 37. NACA66 (MOD, t/c = 0.12) geometry for each slit height 88
Figure 38. Hydrodynamic force on the surface of a Coanda propellers and normal propeller with matched thrust(NACA66 (MOD, t/c = 0.12)) 92
Figure 39. w/jet hydrofoil geometry for each case 94
Figure 40. -Cp distribution with thrust matched according to each case[이미지참조] 96
Figure 41. w/jet hydrofoil geometry for each cover length 98
Figure 42. -Cp distribution with matched thrust according to each cover length[이미지참조] 99
Figure 43. Comparison of flow distribution around the section according to each cover length at r/R=0.84 (Lines: -Cp)[이미지참조] 101
Figure 44. w/jet hydrofoil geometry for each slit position 102
Figure 45. Comparison of KT and 10KQ for each part of propeller according to each slit position[이미지참조] 104
Figure 46. -Cp distribution according to each slit position[이미지참조] 105
Figure 47. Comparison of flow distribution around the section according to each slit position at r/R=0.81 107
Figure 48. Propeller efficiency according to each slit position 108
Figure 49. w/jet hydrofoil geometry for each slit height 109
Figure 50. Comparison of tangential velocity distribution at slit center according to slit height (Cj=0.05)[이미지참조] 112
Figure 51. -Cp distribution according to each slit height (Cj=0.05)[이미지참조] 113
Figure 52. Comparison of KT and 10KQ for each part of propeller according to each slit height[이미지참조] 114
Figure 53. Comparison of thrust PUA distribution on suction side and pressure side according to slit height 116
Figure 54. Comparison of torque PUA distribution on suction side and pressure side according to slit height 117
Figure 55. Comparison of flow distribution around the section according to each slit height at r/R=0.81 118
Figure 56. Propeller efficiency according to each slit height 119
Figure 57. w/jet hydrofoil geometry for each slit-tunnel area ratio 120
Figure 58. Velocity distribution at the center of the slit (Cj=0.050)[이미지참조] 122
Figure 59. -Cp distribution according to each slit-tunnel area ratio (Cj=0.05)[이미지참조] 123
Figure 60. Comparison of KT and 10KQ for each part of propeller according to each slit-tunnel area ratio[이미지참조] 124
Figure 61. Comparison of thrust PUA distribution on suction side and pressure side according to slit-tunnel area ratio 126
Figure 62. Comparison of torque PUA distribution on suction side and pressure side according to slit-tunnel area ratio 127
Figure 63. Comparison of flow distribution around the section according to each slit-tunnel area ratio at r/R=0.81 128
Figure 64. Propeller efficiency according to each slit-tunnel ratio 129
Figure 65. Propeller shape according to injection range 130
Figure 66. -Cp distribution according to each injection range (Cj=0.05)[이미지참조] 132
Figure 67. Comparison of KT and 10KQ for each part of propeller according to each injection range[이미지참조] 134
Figure 68. Comparison of thrust PUA distribution on suction side and pressure side according to injection ratio 136
Figure 69. Comparison of torque PUA distribution on suction side and pressure side according to injection ratio 137
Figure 70. Propeller efficiency according to each injection range 138
Figure 71. w/jet hydrofoil geometry with optimized slit shape 139
Figure 72. -Cp distribution of optimized slit shape with matched thrust[이미지참조] 142
Figure 73. Propeller geometry according to pitch distribution 143
Figure 74. Propeller efficiency with matched thrust according to pitch distribution 147
Figure 75. Comparison of thrust components according to pitch distribution 148
Figure 76. -Cp distribution with thrust matched according to pitch distribution[이미지참조] 150
Figure 77. Comparison of flow distribution around the section according to pitch distribution at r/R=0.81 151