• 제목/요약/키워드: Swirl Jet Impingement Heat Transfer

검색결과 3건 처리시간 0.016초

선회충돌제트에 의한 배열 칩의 열전달 특성에 관한 실험적 연구 (An Experimental Study on Heat Transfer Characteristics of Arrangement Chips by Swirl Jet Impingement)

  • 최재욱;전영우;정인기;박시우
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권4호
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    • pp.624-631
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    • 2004
  • The experimental study on heat transfer characteristics of protruding heated block array as conducted to investigate and to compare the performance of impinging single circular jet in fully developed tube with a twisted tape as a swirl generator. The effects of jet Reynolds number(Re=8700, 13800, 20000. 26500), dimensionless jet-to-block distance(H/d=1. 3, 5. 7) and swirl number(S=0.11, 0.23, 0.30) of the swirl jet on the average Nusselt number for each block and all blocks have been examined. Measurements of heat transfer rate on block surfaces were used naphthalene sublimation technique. Mean velocity and turbulence intensity of the jet along the axis were measured. Potential core length of the jet was 5 times of nozzle diameter because it was fully developed and initially turbulent. With the twisted tape in the nozzle, heat transfer coefficients were higher than those without the twisted tape. which are mainly caused with increasing the jet Reynolds number and swirl number.

원형 선회류제트 충돌면에서의 유동 및 열전달 특성 (Flow and Heat Transfer Characteristics of Impinging Single Circular Swirl Jet on Flat Plate)

  • 장종철;전영우;박시우;정인기
    • 대한기계학회논문집B
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    • 제28권1호
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    • pp.118-125
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    • 2004
  • The experimental study on flow and heat transfer characteristics was conducted to investigate and to compare the performance of swirl jet by a twisted tape as a swirl generator with the performance of impinging single circular jet in fully developed flow tube. The effects of jet Reynolds number(Re=8700, 13800, 20000, 26500), dimensionless distance of nozzle-to-plate(H/d=2, 4, 6, 8) and swirl ratio(S=0.11, 0.23, 0.30) of the jet on the local and average Nusselt number have been examined. Measurements of local heat transfer rate and flow patterns on the jet impinging plate were used naphthalene sublimation technique and flow visualization technique respectively. Mean velocity and turbulence intensity of the jet along the centerline were measured. With a twisted tape in the nozzle exit, average Nusselt number at the around area of stagnation point were higher than those without the twisted tape at H/d=2, 4 and with the increase of Reynolds number. With a twisted tape in the nozzle, in the case of H/d=2, Re=26500 and S=0.11, maximum local Nusselt number at the region of y/d=0 and x/d=0.44 was obtained.