Heat Transfer Measurements by a Round Impinging Jet on a Rib-Roughened Flat Plate

표면조도를 가진 평판에서 원형충돌제트에 의한 열전달 측정

  • 이대희 (인제대학교 기계자동차공학부) ;
  • 김윤택 (인제대학교 대학원 기계공학과) ;
  • 정승훈 (인제대학교 대학원 기계공학과) ;
  • 정영석 (서울대학교 대학원 기계항공공학부)
  • Published : 2000.11.02

Abstract

This study is to investigate the heat transfer characteristics the for a round turbulent jet impinging on the flat plate with and without rib. Liquid crystal/transient method was used to determine the Nusselt number distributions along the surface. The temperature on the surface was measured using liquid crystal and a digital color image processing system. The experiments were made fur the jet Reynolds number (Re) 23,000, the dimensionless nozzle-to-surface distance (L/d) from 2 to 10, and the rib type [height ($d_1$) 2mm, pitch (p) from 12 to 36mm]. It was found that for $L/d{\ge}6$ the average Nusselt numbers on the flat plate with rib type C ($p/d_1=16$) are higher than those without rib, mainly due to an increase in the turbulent intensity caused by flow separation, recirculation and reattachment on the wall surface.

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