Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
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Experimental and Numerical Analysis for Effects of Two Inclined Baffles on Heat Transfer Augmentation in a Rectangular Duct

사각 덕트 내에 설치된 2개의 경사진 배플에 의한 열전달 증진 효과에 관한 실험 수치해석

  • Kang, Ho-Keun (Institute of Marine Industry, Gyeongsang National University) ;
  • Ahn, Soo-Whan (Department of Mechanical and Aerospace Engineering, Institute of Marine Industry, Gyeongsang National University) ;
  • Putra, Ary Bachtiar Krishna (Department of Mechanical and System Engineering, Graduate School, Gyeongsang National University)
  • 강호근 (경상대학교 해양산업연구소) ;
  • 안수환 (경상대학교 기계항공공학과.해양산업연구소) ;
  • Published : 2007.11.10
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Abstract

Baffles enhance heat transfer by disturbing boundary layer and bulk flow, creating impingement, and increasing heat transfer surface area. This study was performed to determine how the two inclined baffles (${\alpha}=5^{\circ}$ perforated models) placed at a rectangular channel affect heat transfer and associated friction characteristics. The parametric effects of perforated baffles (3, 6 and 12 holes) and flow Reynolds number ranging from 28,900 to 61,800 on the heated target surface are explored. Comparisons of the experimental data with the numerical results by commercial code CFX 10.0 are presented. As for the investigation of heat transfer behaviors on local Nusselt number with two baffles placed at $x/D_h=0.8$ and $x/D_h=8.0$ of the edge of baffles, it is evident that the inclined perforated baffles augment overall heat transfer significantly by both jet impingement and boundary layer separation. There exists an optimum perforation density to maximize heat transfer coefficients; i.e., the average Nusselt number increases with increasing number of holes, but the friction factor decreases with an increase in the hole number placed at baffles.

Keywords

References

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