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B. K. P. Ary(아리바시아),S. W. Ahn(안수환),Y. S. Jeun(전용수) 한국동력기계공학회 2007 한국동력기계공학회 학술대회 논문집 Vol.- No.-
This experimental study investigates the local heat transfer enhancement characteristics and the associated frictional head loss in a rectangular channel with a single inclined baffle. Four different types of the baffle are used. The inclined baffles have the width of 19.8 ㎝, the square diamond of 2.55 ㎝ × 2.55 ㎝, and the inclination angle of 5°. Reynolds number is varied between 23,000 and 57,000. Results show that the heat transfer and friction factor depend significantly on the number of baffle holes and Reynolds number. The friction factor decreases with increasing Reynolds number and the number of holes on the baffle. It is found that the heat transfer performance of baffle type Ⅱ (3 hole baffle) has the best values.
채널 내에 설치된 2개의 경사진 배플에 의한 열전달 효과에 관한 수치해석
S. W. Ahn(안수환),H. K. Kang(강호근),B. K. P. Ary(아리바시아) 한국동력기계공학회 2007 한국동력기계공학회 학술대회 논문집 Vol.- No.-
Baffles enhance heat transfer by disturbing boundary layer and bulk flow, creating impingement, and increasing heat transfer surface area. This study was performed to determine how the two inclined baffles (α=5°; perforated models) placed at a rectangular channel affect heat transfer and associated friction characteristics. The parametric effects of perforated baffles (3, 6 and 12 holes) and flow Reynolds number ranging from 28,900 to 61,800 on the heated target surface are explored. Comparisons of the experimental data with the numerical results by commercial code CFX 10.0 are presented. As for the investigation of heat transfer behaviors on local Nusselt number with two baffles placed at <SUP>χ</SUP>/Dh =0.8 and <SUP>χ</SUP>/Dh=8.0 of the edge of baffles, it is evident that the inclined perforated baffles augment overall heat transfer significantly by both jet impingement and boundary layer separation. There exists an optimum perforation density to maximize heat transfer coefficients; i.e., the average Nusselt number increases with increasing number of holes, but the friction factor decreases with an increase in the hole number placed at baffles.