Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
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Numerical Analysis on the Initial Cool-down Performance Inside an Automobile for the Evaluation of Passenger's Thermal Comfort

차량 내부 탑승자의 쾌적성 평가를 위한 초기 냉방운전 성능에 대한 수치해석적 연구

  • Kim, Yoon-Kee (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Yang, Jang-Sik (Clean Coal Center, Pusan National University) ;
  • Baek, Je-Hyun (Department of Mechanical Engineering, Pusan National University) ;
  • Kim, Kyung-Chun (Department of Mechanical Engineering, POSTECH) ;
  • Ji, Ho-Seong (Department of Mechanical Engineering, POSTECH)
  • 김윤기 (부산대학교 기계공학과) ;
  • 양장식 (부산대학교 화력발전에너지분석기술센터) ;
  • 백제현 (포항공과대학교 기계공학과) ;
  • 김경천 (부산대학교 기계공학부) ;
  • 지호성 (부산대학교 기계공학부)
  • Received : 2010.01.13
  • Accepted : 2010.03.03
  • Published : 2010.09.01
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Abstract

Cool-down performance after soaking is important because it affects passenger's thermal comfort. The cooling capacity of HVAC system determines initial cool down performance in most cases, the performance is also affected by location, and shape of panel vent, indoor seat arrangement. Therefore, optimal indoor designs are required in developing a new car. In this paper, initial cool down performance is predicted by CFD(computational fluid dynamics) analysis. Experimental time-averaging temperature data are used as inlet boundary condition. For more reliable analysis, real vehicle model and human FE model are used in grid generation procedure. Thermal and aerodynamic characteristics on re-circulation cool vent mode are investigated using CFX 12.0. Thermal comfort represented by PMV(predicted mean vote) is evaluated using acquired numerical data. Temperature and velocity fields show that flow in passenger's compartment after soaking is considerably unstable at the view point of thermodynamics. Volume-averaged temperature is decreased exponentially during overall cool down process. However, temperature monitored at different 16 spots in CFX-Solver shows local variation in head, chest, knee, foot. The cooling speed at the head and chest nearby panel vent are relatively faster than at the knee and foot. Horizontal temperature contour shows asymmetric distribution because of the location of exhaust vent. By evaluating the passenger's thermal comfort, slowest cooling region is found at the driver's seat.

Keywords

References

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