Effects of Bleed Hole on Heat/Mass Transfer in a Rotating Channel with Transverse Ribs

90도 요철이 설치된 회전덕트에서 유출홀이 열/물질전달에 미치는 영향

  • 박석환 (연세대학교 대학원 기계공학부) ;
  • 전윤흥 (연세대학교 대학원 기계공학부) ;
  • 김경민 (연세대학교 대학원 기계공학부) ;
  • 이동현 (연세대학교 대학원 기계공학부) ;
  • 조형희 (연세대학교 기계공학부)
  • Published : 2005.12.01

Abstract

The present study investigates the effects of bleed flow on heat/mass transfer and pressure drop in a rotating channel with transverse rib turbulators. The hydraulic diameter ($D_h$) of the square channel is 40.0 mm. The bleed holes are located between the rib turburators on leading surface and the hole diameter (d) is 4.5 mm. The square rib turbulators are installed on both leading and trailing surfaces. The rib-to-rib pitch is 10.0 times of the rib height (e) and the rib height-to-hydraulic diameter ratio ($e/D_h$) is 0.055. The tests were conducted at various rotation numbers (0, 0.2, 0.4), while the Reynolds number and the rate of bleed flow to main flow were fixed at 10,000 and 10%, respectively. The results suggest that the heat/mass transfer characteristics in the internal cooling passage are influenced by rib turbulators, bleed flow and the Cariolis force induced by rotation. For the rotating ribbed passage with bleed flow, the heat/mass transfer on the leading surface is hardly affected by bleed flow, but that on the trailing surface decreases due to the diminution of main flow. The results also show that the friction factor decreases with the bleed flow.

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