Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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The Effect of the Prandtl Number on Natural Convection in a Square Enclosure with Inner Cylinder of Various Positions

Prandtl 수 변화가 다양한 위치의 원형실린더가 존재하는 정사각형 밀폐계 내부 자연대류 현상에 미치는 영향

  • Seong, Seon Yu (School of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Choi, Changyoung (School of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Ha, Man Yeong (School of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Yoon, Hyun Sik (Global Core Research Center for Ships and Offshore Plants, Pusan Nat'l Univ.)
  • 성선유 (부산대학교 기계공학부) ;
  • 최창영 (부산대학교 기계공학부) ;
  • 하만영 (부산대학교 기계공학부) ;
  • 윤현식 (조선해양플랜트 글로벌 핵심 연구센터)
  • Received : 2014.04.11
  • Accepted : 2014.07.23
  • Published : 2014.11.01
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Abstract

This paper presents a numerical study conducted for analyzing the effect of the Prandtl number on natural convection in a square enclosure with an inner circular cylinder in various positons. Several Prandtl numbers (Pr = 0.1, 0.7, and 7) and Rayleigh numbers (Ra = $10^3$, $10^4$ and $10^5$) are considered in the numerical study, along with different positions of the inner circular cylinder. The position of the inner circular cylinder is changed in steps of 0.1 in the range of -0.2 to 0.2. The effect of the Prandtl number on natural convection in the enclosure is analyzed on the basis of the thermal and flow fields and the distribution of the Nusselt number. Regardless of the position of the cylinder, when the Rayleigh number is $10^5$, the surface-averaged Nusselt number of the inner cylinder and the enclosure increases as the Prandtl number increases.

본 연구는 다양한 위치의 원형 실린더가 존재하는 사각 밀폐계에서 Prandtl 수 변화에 따른 밀폐계 내부의 자연대류 현상에 대한 수치해석을 수행하였다. Rayleigh 수가 $10^3$, $10^4$, $10^5$ 그리고 다양한 위치의 내부 원형 실린더에 대해서 Prandtl 수를 0.1, 0.7, 7 로 변화시키며 Prandtl 수의 영향을 분석하였다. 내부 원형 실린더의 위치는 -0.2 에서 0.2 까지 0.1 간격으로 변화시켰다. Prandtl 수의 변화에 따른 밀폐계 내부의 자연대류 현상은 밀폐계 내부의 온도장과 유동장 및 표면 평균 Nusselt 수의 분포를 바탕으로 분석하였다. Rayleigh 수가 $10^5$ 일 때 내부 실린더의 위치에 상관없이 Prandtl 수가 증가할수록 평균 Nusselt 수는 증가하였다.

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References

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