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

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Inner Circular Cylinder Size on Three-Dimensional Natural Convection in Cubical Enclosure

내부 원형 실린더의 크기가 정육면체 밀폐계 내부의 3 차원 자연대류 현상에 미치는 영향

  • 서영민 (부산대학교 기계공학부) ;
  • 최창영 (부산대학교 기계공학부) ;
  • 하만영 (부산대학교 기계공학부) ;
  • 박상후 (부산대학교 기계공학부/정밀정형 및 금형가공 연구소)
  • Received : 2014.04.11
  • Accepted : 2014.05.27
  • Published : 2014.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

This study evaluates the effect of a heated circular cylinder's size on three-dimensional natural convection in a cubical enclosure. The Rayleigh number was varied between $10^3$ and $10^5$, and the Prandtl number was maintained at 0.7. In this study, the radius of the circular cylinder was changed by 0.1 L within a range of 0.1-0.4 L. The thermal and fluid flow characteristics were regarded to be independent of time in the range of the Rayleigh number and cylinder radius considered in this study. The surface-averaged Nusselt numbers of the cylinder and the enclosure were found to increase with the increase in the radius of the cylinder. The effect of the cylinder's size on natural convection in the enclosure was analyzed across the thermal and flow fields, and the distributions of the Nusselt numbers.

본 연구는 정육면체 밀폐계 내부에 존재하는 고온의 원형 실린더의 크기 변화에 따른 밀폐계 내부의 3 차원 자연대류 현상에 대한 수치해석을 수행하였다. 본 연구에서 고려한 Rayleigh 수는 $10^3$부터 $10^5$까지며 Prandtl 수는 0.7 이다. 내부 원형 실린더의 반경은 0.1L 부터 0.4L 범위에서 0.1L 간격으로 변경하였다. 본 연구에서 고려한 모든 Rayleigh 수와 실린더 반경의 범위에서 열유동장은 정상 상태의 특성을 보였다. 내부 원형 실린더의 크기가 증가하여 실린더 표면과 밀폐계 벽면이 가까워 질수록 실린더 표면과 밀폐계 벽면의 평균 Nusselt 수는 증가하였다. 내부 원형 실린더의 크기 변화에 따른 정육면체 밀폐계 내부의 자연대류 현상은 온도장, 유동장 및 표면 평균 Nusselt 수의 분포를 바탕으로 분석하였다.

Keywords

References

  1. Angeli, D., Pagano, A., Corticelli, M.A., Fichera, A. and Barozzi, G.S., 2011, "Bifucations of Natural Convection Flows from an Enclosed Cylindrical Heat Source," Frontiers in Heat and Mass Transfer, Vol. 2, pp. 023003.
  2. Xu, X., Yu, Z., Hu, Y., Fan, L. and Cen, K., 2010, "A Numerical Study of laminar Natural Convective Heat Transfer around a Horizontal Cylinder inside a Concentric Air-Filled Triangular Enclosure," International Journal of Heat and mass Transfer, Vol. 53, pp. 345-355. https://doi.org/10.1016/j.ijheatmasstransfer.2009.09.023
  3. Corvaro, F. and Paroncini, M., 2009, "An Experimental Study of Natural Convection in a Differentially Heated Cavity through a 2D-PIV System," International Journal of Heat and Mass Transfer, Vol. 52, pp. 335-365.
  4. Butler, C., Newport, D. and Geron, M., 2013, "Natural Convection Experiments on a Heated Horizontal Cylinder in a Differentially Heated Square Cavity," Experimental Thermal and Fluid Science, Vol. 44, pp. 199-208. https://doi.org/10.1016/j.expthermflusci.2012.06.009
  5. Kuehn, T. H. and Goldstein, R. J., 1976, "An Experimental and Theoretical Study of Natural Convection in the Annulus between Horizontal Concentric Cylinders," Journal of Fluid Mechanics, Vol. 74, pp. 695-719. https://doi.org/10.1017/S0022112076002012
  6. Moukalled, F. and Acharya, S., 1996, "Natural Convection in the Annulus Between Concentric Horizontal Circular and Square Cylinders," Journal of Thermophysics and Heat Transfer, Vol.10, pp. 524-531. https://doi.org/10.2514/3.820
  7. Shu, C. and Zhu, Y. D., 2002, "Efficient Computation of Natural Convection in a Concentric Annulus between an Outer Square Cylinder and an Inner Circular Cylinder," International Journal for Numerical Methods in Fluids, Vol. 38, pp. 429-445. https://doi.org/10.1002/fld.226
  8. Angeli, D., Levoni, P. and Barozzi, G.S., 2008, "Numerical Predictions for Stable Buoyant Regimes within a Square Cavity Containing a Heated Horizontal Cylinder," International Journal of Heat and Mass Transfer, Vol. 51, pp. 553-565. https://doi.org/10.1016/j.ijheatmasstransfer.2007.05.007
  9. Kim, B. S., Lee, D. S., Ha, M. Y. and Yoon, H. S., 2008, "A Numerical Study of Natural Convection in a Sqaure Enclosure with a Circular Cylinder at Different Vertical Locations," International Journal of Heat and Mass Transfer, Vol. 51, pp. 1888-1906. https://doi.org/10.1016/j.ijheatmasstransfer.2007.06.033
  10. Chan, A.M.C. and Banerjee, S., 1979, "A Numerical Study of Three-Dimensional Roll Cells within Rigid Boundaries," Journal of Heat Transfer, Vol. 101, pp. 233-237. https://doi.org/10.1115/1.3450952
  11. Yoon, H. S., Ha, M. Y., Kim, B. S. and Yu, D. H., 2009, "Effect of the Position of a Circular Cylinder in a Square Enclosure on Natural Convection at Rayleigh Number of $10^7$," Physics of Fluids, Vol. 21, 047101. https://doi.org/10.1063/1.3112735
  12. Gray, D. and Giorgini, A., 1976, "The Validity of the Boussinesq Approximation for Liquids and Gases," International Journal of Heat and Mass Transfer, Vol. 19, pp. 545-551. https://doi.org/10.1016/0017-9310(76)90168-X
  13. Kim, J., Kim, D. and Choi, H., 2001, "An Immersed-Boundary Finite Volume Method for Simulations of Flow in Complex Geometries," Journal of Computational Physics, Vol. 171, pp. 132-150. https://doi.org/10.1006/jcph.2001.6778
  14. Kim, J. and Choi, H., 2004, "An Immersed-Boundary Finite-Volume Method for Simulation of Heat Transfer in Complex Geometries," KSME International Journal, Vol. 18, pp. 1026-1035.
  15. Fiscaletti, D., Angeli, D., Tarozzi, L. and Barozzi, G.S., 2013, "Buoyancy-Induced Transitional Flows around an Enclosed Horizontal Cylinder: An Experiment," International Journal of Heat and Mass Transfer, Vol. 58, pp. 619-631. https://doi.org/10.1016/j.ijheatmasstransfer.2012.11.039