Validity Review of Mixed Convection Flow Regime Map in Vertical Cylinders

수직 원형관내 혼합대류 유동영역지도의 유효성 검토

  • Kang, Gyeong-Uk (Research & Development Institute, Korea Radioactive Waste Agency) ;
  • Kim, Hyoung-Jin (Research & Development Institute, Korea Radioactive Waste Agency) ;
  • Yoon, Si-Tae (Research & Development Institute, Korea Radioactive Waste Agency) ;
  • Chung, Bum-Jin (Department of Nuclear Engineering, Kyung Hee University)
  • 강경욱 (한국원자력환경공단 기술연구소) ;
  • 김형진 (한국원자력환경공단 기술연구소) ;
  • 윤시태 (한국원자력환경공단 기술연구소) ;
  • 정범진 (경희대학교 원자력공학과)
  • Received : 2014.04.15
  • Accepted : 2014.09.17
  • Published : 2014.09.30


The existing flow regime map on mixed convection in vertical cylinders was investigated through an analysis of original literatures and its re-formation. The original literatures related to the existing map were reviewed. Using the investigated data and heat transfer correlations, the map was redrawn independently, and compared with the existing map. The redrawn map showed that mixed convection regime was not curved lines but straight lines and the transition regime was unable to be reproduced. Unlike the existing map with a little data, there are lots of data in the redrawn map. The reviews revealed that the existing map used the data selectively among the experimental and theoretical results, and a detailed description for lines forming mixed convection and transition regime was not provided. While considerable studies on mixed convection have been performed since that of Metais and Eckert, the existing map has still been used as the best method to distinguish natural, forced and mixed convection regime.

본 연구에서는 기존에 알려진 수직 원형관내 혼합대류 유동영역지도에 대하여 원 문헌의 분석과 재구성을 통해 지도의 유효성 검토를 수행하였다. 지도를 구성하는 원 문헌을 수집하여 내용을 정리하였고 조사한 데이터와 대류열전달 상관식을 활용하여 독립적으로 지도를 재구성하고 기존의 지도와 비교하였다. 재구성한 지도에는 혼합대류 영역이 곡선이 아니라 직선으로 나타났으며 천이영역을 나타내는 것은 재현되지 않았다. 일부 데이터만 포함된 기존의 지도와 달리 재구성 지도에는 상당히 많은 양의 데이터가 포함됐다. 기존의 유동영역지도는 활용된 데이터가 선택적으로 사용되었고, 혼합대류와 천이영역을 나타내는 실선 대해 언급되지 않았으며 불확실도 분석을 통한 정보를 제공하지 않았기 때문에 신뢰할 수 없다고 판단된다. Metais와 Eckert의 연구 이후, 혼합대류에 관한 많은 연구가 수행되었으나 대류의 유동영역을 구분하는 방법으로 기존의 지도가 지금까지 활용되고 있다.



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