| Title |
Experimental and Numerical Analysis for Effects of Two Inclined Baffles on Heat Transfer Augmentation in a Rectangular Duct |
| Authors |
강호근(Ho-Keun Kang) ; 안수환(Soo-Whan Ahn) ; Ary Bachtiar Krishna Putra(Ary Bachtiar Krishna Putra) |
| Keywords |
열전달 증진 ; 배플 ; 누셀트수 ; 마찰계수 Heat transfer augmentation ; Baffle ; Nusselt number ; Friction factor |
| Abstract |
Baffles enhance heat transfer by disturbing boundary layer and bulk flow, creating impingement, and increasing heat transfer surface area. This study was performed to deter-mine 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 x/Dh=0.8 and at x/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. |