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

The Korean Society of Mechanical Engineers (대한기계학회)
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Enhancement of Impinging Jet Heat Transfer Using Triangular Multi-Tabs

삼각형 멀티 탭을 이용한 충돌제트 열전달 향상 연구

  • 이정욱 (포항공과대학교 대학원 기계공학과) ;
  • 이상준 (포항공과대학교 기계공학과)
  • Published : 2004.10.01
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Abstract

The effect of triangular tabs attached at the perimeter of jet nozzle on heat transfer enhancement was investigated experimentally. The modified flow structure was visualized using a smoke-wire method. Four different types of jet nozzle having 0, 4, 6 and 8 tabs were tested at jet Reynolds number Re=15,000 to investigate the effect of tabs on the variation of heat transfer rate. The local and average Nusselt numbers are increased with increasing the number of tabs. At nozzle-to-plate distance of L/D=4, the average Nusselt number was increased about 9.9% at Re=15,000 in the impingement region for the case of 8 tabs attachment. As the nozzle-to-plate distance increases, however, the heat transfer enhancement effect of triangular tabs is reduced. For the case of 4 tabs, the heat transfer enhancement is not so distinctive at L/D=8. As the protrusion depth of tabs into the jet flow increases, the heat transfer rate is also enhanced when the nozzle-to-plate distance is smaller than L/D=6.

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References

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