Department News
Unraveling the Nature of Two-Phase Flow in Polymer Electrolyte Fuel Cells
Seminar Date
2005-07-15
Author
임아주
Date
2005-07-01
Views
1964
1. 제 목 : Unraveling the Nature of Two-Phase Flow in Polymer Electrolyte Fuel Cells
2. 연 사 : Matthew M. Mench
Assistant Professor of Mechanical Engineering
Director, Fuel Cell Dynamics and Diagnostics Laboratory (FCDDL)
The Pennsylvania State University , U.S.A.
3. 일 시 : 2005년 7월 15일 (금) 10:00 ~ 11:00
4. 장 소 : 301동 1512호
5. 요 약 :
For high ionic conductivity, and thus high performance, the polymer electrolyte membrane must have high moisture content. However, if water condenses, reactant availability at the electrode can be hindered, resulting in severe performance loss. Performance loss resulting from liquid water accumulation is commonly referred to as ‘flooding’, but there exists a lack of fundamental understanding of the exact nature of this phenomenon. Modeling of flooding is extremely complex, considering the highly anisotropic thin-film porous media involved, and the highly coupled nature of the related heat transfer, fluid mechanics, electrochemistry, and thermodynamic processes. In order to model the performance loss from flooding, the conventional approach has been to modify the effective gas-phase diffusivity into the porous diffusion media (DM) resulting from DM pore-blockage, which is assumed to be homogenously distributed. Although models using this approach can simulate polarization behavior, this physical model of flooding has not yet proven to be an accurate representation of fact.
To date, there has been a relative paucity of research in experimental visualization and quantification of the liquid water distribution. The Pennsylvania State University Fuel Cell Dynamics and Diagnostics Laboratory (FCDDL) is approaching this lack of comprehensive understanding and model validation with an array of complimentary technologies, including the use of neutron imaging, transparent cell visualization, segmented diagnostic cells, unique species measurement diagnostics, and computational fluid dynamics modeling. This talk will discuss the various approaches developed to date, and focus specifically on the current understanding of the true nature of flooding in polymer electrolyte fuel cells, which is emerging as significantly different from the pore-filling concept of flooding that is modeled in literature.
6. 약 력 :
Ph. D. Mechanical Engineering, The Pennsylvania State University, 2000
M. S. Mechanical Engineering, The Pennsylvania State University, 1996
B. S. Mechanical Engineering, The Pennsylvania State University, 1994
7. 문 의 : 기계항공공학부 김 민 수 교수 (☎880-8362)
2. 연 사 : Matthew M. Mench
Assistant Professor of Mechanical Engineering
Director, Fuel Cell Dynamics and Diagnostics Laboratory (FCDDL)
The Pennsylvania State University , U.S.A.
3. 일 시 : 2005년 7월 15일 (금) 10:00 ~ 11:00
4. 장 소 : 301동 1512호
5. 요 약 :
For high ionic conductivity, and thus high performance, the polymer electrolyte membrane must have high moisture content. However, if water condenses, reactant availability at the electrode can be hindered, resulting in severe performance loss. Performance loss resulting from liquid water accumulation is commonly referred to as ‘flooding’, but there exists a lack of fundamental understanding of the exact nature of this phenomenon. Modeling of flooding is extremely complex, considering the highly anisotropic thin-film porous media involved, and the highly coupled nature of the related heat transfer, fluid mechanics, electrochemistry, and thermodynamic processes. In order to model the performance loss from flooding, the conventional approach has been to modify the effective gas-phase diffusivity into the porous diffusion media (DM) resulting from DM pore-blockage, which is assumed to be homogenously distributed. Although models using this approach can simulate polarization behavior, this physical model of flooding has not yet proven to be an accurate representation of fact.
To date, there has been a relative paucity of research in experimental visualization and quantification of the liquid water distribution. The Pennsylvania State University Fuel Cell Dynamics and Diagnostics Laboratory (FCDDL) is approaching this lack of comprehensive understanding and model validation with an array of complimentary technologies, including the use of neutron imaging, transparent cell visualization, segmented diagnostic cells, unique species measurement diagnostics, and computational fluid dynamics modeling. This talk will discuss the various approaches developed to date, and focus specifically on the current understanding of the true nature of flooding in polymer electrolyte fuel cells, which is emerging as significantly different from the pore-filling concept of flooding that is modeled in literature.
6. 약 력 :
Ph. D. Mechanical Engineering, The Pennsylvania State University, 2000
M. S. Mechanical Engineering, The Pennsylvania State University, 1996
B. S. Mechanical Engineering, The Pennsylvania State University, 1994
7. 문 의 : 기계항공공학부 김 민 수 교수 (☎880-8362)
