A numerical analysis was performed to study PEMFC performance characteristics depending on the flow direction of cathode reactant gas, cathode relative humidity, and porosity of gas diffusion layer. As cathode relative humidity decreases and porosity increases, current density increases due to better diffusion of reactant gas to cathode surface. As current density increases, power density increases initially and then decreases with its maximum located around current density value of 2.2 Amperes per square centimeter. From the analysis of current density distribution inside membrane, the counter-flow cases show more uniform profile across the membrane than the co-flow cases due to more uniform reactant gas supply.

Abstract
 1. 서론
 2. 연구 방법
  2.1 수치해석모델
  2.2 지배 방정식
 3. 결과 및 토의
  3.1 I-V, I-P 성능곡선 분석
  3.2 전해질내의 전류밀도 분석
 4. 결론
 후기
 References

• 류의환(공주대학교 대학원 기계공학과) | Eui Hwan Ryu
• 김우태(공주대학교 기계자동차공학부) | Woo Tae Kim Corresponding Author