표제지
요약문
ABSTRACT
목차
NOMENCLATURE 12
제1장 서론 21
제2장 수치해석적 모델 27
2.1. 모델 가정 29
2.2. 3차원 이상 멀티스케일 PEMFC 모델 30
2.3. 압착력이 접촉 저항에 미치는 영향성 31
2.4. Forchheimer 관성 효과 적용 32
2.5. 작동/경계 조건 및 수치 구현 33
제3장 대리 모델 및 다목적 최적화 모델 35
제4장 다목적 최적화 모델 공식 38
4.1. 설계변수 선정과 목적함수 공식 39
4.2. 대리 모델 구축 40
제5장 결과 및 논의 41
5.1. 대리 모델의 성능 예측 평가 41
5.2. 각 목적함수에 설계변수가 미치는 영향성 분석 42
5.3. △P,Vcell,ISD에 따른 다목적 최적화 결과[이미지참조] 44
제6장 결론 49
REFERENCES 88
Table 1. Multiscale, Two-phase PEMFC model: Governing equations. 51
Table 2. Multiscale, Two-phase PEMFC model. 52
Table 3. Physiochemical, kinetic, and transport properties for individual PEMFC components. 53
Table 4. Two-phase mixture correlations. 54
Table 5. Transport properties for the electrolyte. 56
Table 6. Properties of CLs for the microscale CL simulations. 57
Table 7. Correlations for the microscale CL model. 58
Table 8. Electronic and thermal contact resistances between individual PEMFC components. 61
Table 9. Darcy-Forchheimer's model. 62
Table 10. Cell dimensions and operating conditions. 63
Table 11. Boundary conditions. 64
Table 12. Comparison of results between reference case and optimal points at Iavg=2.5A/cm².[이미지참조] 65
Figure 1. (a) Macro and microscale computational domains of PEMFC with the coupling variables exchanged during multiscale simulations. (b) Results... 66
Figure 2. Schematic of orifice-shaped flow field designs with channel design variables for optimization method 67
Figure 3. Scatter plots for the training data (131 points) and the test data (20 points) (a) Vcell, (b) △P (c) ISD.[이미지참조] 70
Figure 4. Effects of cathode orifice design variables on the △P,Vcell,ISD based on MLP prediction at Iavg=2.5 A/cm² with consideration of...[이미지참조] 73
Figure 5. Effects of area of orifice on the △P,Vcell,ISD based on LHS data.[이미지참조] 74
Figure 6. Pareto front with scatter plots of the sample data. The LHS point represents values obtained from the 3D PEMFC model, while the pareto front... 77
Figure 7. Polarization curves and △P curves for the reference and three optimal designs. The operating pressure is 1.5 bar at the operating current... 78
Figure 8. Oxygen concentration distribution contours over the middle of the cCL for the Ref and three optimal designs, observed at an operating current... 79
Figure 9. Liquid saturation distribution contours over the middle of the cCL for the Ref and three optimal designs, observed at an operating current density... 80
Figure 10. Liquid saturation contours, accompanied by velocity vectors in the cGDL at an operating current density Iavg=2.5A/cm² and 50 %...[이미지참조] 83
Figure 11. Current density distribution contours over the middle of the membrane for the Ref and three optimal designs, observed at an operating... 84
Figure 12. Breakdown of activation, ohmic, and concentration overpotentials for Ref and three optimal designs at the operating current density of Iavg=...[이미지참조] 85