Effects of Baffles on Heat Transfer and Friction Factors in a Rectangular Channel

사각채널에 설치된 배플이 열전달과 마찰계수에 미치는 효과

  • 안수환 (경상대학교 해양산업연구소 기계항공공학부) ;
  • 강호근 (경상대학교 해양산업연구소) ;
  • 배성택 (경상대학교 대학원 기계시스템공학과) ;
  • 송민호 (주식회사 태건)
  • Published : 2006.09.30

Abstract

The present work investigates the local heat transfer characteristics and the associated frictional loss in a rectangular channel with inclined solid and perforated baffles to obtain the basic design data for gas turbine. Five different geometries of baffles such as 1) solid (without hole), 2) three holes, 3) six holes, 4) nine holes, 5) twelve holes were covered. A combination of two baffles of same overall size is used. The flow Reynolds number is ranged from 28,900 to 70,100. The placement of baffles augments the overall heat transfer greatly by combining both jet impingement and the boundary layer separation. The present results show that the average Nusselt number distribution is strongly dependent on number of holes in the baffle plates, i.e., the average Nusselt number increases with increasing number of holes. The friction factor decreases also with increasing the number of holes. however. its value increases with increasing the Reynolds number.

Keywords

References

  1. Z. H. Lin, Y. J. Chou and Y. H. Hung, 'Heat Transfer Behaviours of a Confined Slot Jet Impingement,' Int. J. Heat Mass Transfer, Vol. 40, No. 5, pp. 1095-3706, 1997 https://doi.org/10.1016/0017-9310(96)00135-4
  2. R. J. Goldstein and W. S. Seol, 'Heat Transfer to a Row of Impinging Circular Air Jets Including the Effect of Entrainment,' Int. J. Heat Mass Transfer, Vol. 34, No. 8, pp. 2133-2147, 1991 https://doi.org/10.1016/0017-9310(91)90223-2
  3. A. H. Beitelmal, M. A. Saad and C. D. Patel, 'The Effect of Inclination on the Heat Transfer Between a Flat Surface and an Impinging Twodimensional Air Jet,' Int. J. Heat Fluid Flow, Vol. 21, No. 2, pp. 156-163, 2000 https://doi.org/10.1016/S0142-727X(99)00080-6
  4. C. Berner, F. Durst and D. M. McEligot, 'Flow Around Baffles,' ASME J. Heat Transfer 106, 743-749, 1984 https://doi.org/10.1115/1.3246747
  5. M. A. Habib, A. M. Mobarak, M. A. Sallak, E. A. Abdel Hadi and R. I. Affify, 'Experimental Investigation of Heat Transfer and Flow over Baffles of Different Heights,' ASME J. Heat Transfer 116 (2), 363-368, 1994 https://doi.org/10.1115/1.2911408
  6. P. Dutta and S. Dutta, 'Effect of Baffle Size, Perforation on Internal Heat Transfer Enhancement,' Int. J. Heat Mass Transfer, Vol. 41, No. 19, pp. 2133-2147, 1998
  7. K. H. Ko and N. K. Anand, 'Use of Porous Baffles to Enhance Heat Transfer in a Rectangular Channel,' Int. J. Heat Mass Transfer, Vol. 46, No. 22, pp. 4191-4199, 2003 https://doi.org/10.1016/S0017-9310(03)00251-5
  8. I. Ziolkowska, M. Dolata and D. Ziolkowski, 'Heat and Momentum Transfer in Fluids Heated in Tubes with Turbulence Generators at Moderate Prandtl and Reynolds Numbers,' Int. J. Heat Mass Transfer, Vol. 42, No. 4, pp. 613-627, 1999 https://doi.org/10.1016/S0017-9310(98)00201-4
  9. Y. T. Yang and C. Z. Hwang, 'Calculation of Turbulence Flow and Heat Transfer in a Porous-baffled Channel,' Int. J. Heat Mass Transfer, Vol. 46, No. 5, pp. 771-780, 2003 https://doi.org/10.1016/S0017-9310(02)00360-5
  10. J. A. Khan, J. Hinton and S. C. Baxter, 'Enhancement of Heat Transfer with Inclined Baffles and Ribs Combined,' J. Enhanced Heat Transfer 9 (3-4), 137-151, 2002 https://doi.org/10.1080/10655130215738
  11. P. R. Chandra, M. E. Niland and J. C. Han, 'Turbulent Flow Heat Transfer and Friction in a Rectangular Channel with Varying Number of Ribbed Walls,' J. Turbomachinery, Vol. 119, No. 2, pp. 374-380, 1997 https://doi.org/10.1115/1.2841121
  12. P. Dutta and A. Hossain, 'Internal Cooling Augmentation in Rectangular Channel Using Two Inclined Baffles,' Int. J. Heat and Fluid Flow, Vol. 26, pp. 223-232, 2005 https://doi.org/10.1016/j.ijheatfluidflow.2004.08.001
  13. S. K. Oh, W. C. Kim, S. W. Ahn, H. K. Kang and M. H. Kim, 'An Experimental Studies on Heat Transfer and Friction Factor in a Square Channel with Varying Number of Ribbed Walls,' 한국마린엔지니어링학회지, Vol. 29, No. 3, pp. 281-289, 2005
  14. 강호근, 안수환, 배성택, 이대희, '거친 사각채널에서 열전달과 유체유동 특성에 관한 실험 및 수치해석,' 한국마린엔지니어링학회지, Vol. 30, No. 2, pp. 275-283, 2006