Pressure　Loss　Through　Sharp　180　deg　Turn　in　a　Relatively　Short　Two－Pass　Smooth　and　Rib－Roughened　Channel

作     者：C.Y. Zhao W.Q. Tao(School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China) 

作者机构：School of Energy and Power Engineering Xi’an Jiaotong University Xi’an China 

出 版 物：《Journal of Thermal Science》 (热科学学报（英文版）)

年 卷 期：1995年第4卷第2期

页      面：109-116页

核心收录：

学科分类：080704[工学-流体机械及工程] 08[工学] 0807[工学-动力工程及工程热物理] 

主　　题：resistance cofficient rib-roughened channel. 

摘      要：The local pressure distributions and resistance coefficients (f1 and f2) through the sharp 180 deg turn in a relatively short (L/De = 4) two-pass smooth and rib-roughened channel were investigated for a Reynolds number range of 1.0 × 103 - 9.0 × 103. The rib pitch-to-height ratios (p/e) were 5,10, and 20. The rib height-to-hydraulic diameter ratios (e/De) were 0.025, 0.050 and 0.10, and the rib angles of attack (α) were 90, 45, 60, -45, and -60 deg. Ribs were installed not only in before and after turn regions but also in turn region. The results show that the resistance coefficients remain approximately constant when Reynolds number is more than 3.0×104. The effects of the rib condguration (rib spacing, rib height, and rib orientation) on the inlet straight duct resistance coefficient (f2) were significant, however, their effects on the overall resistance coefficient (f1) were diluted by the sharp-180 turn. For this relatively short channel (L/De=4), the overall resistance coefficient (f1) was greatly affected by the sharp turn. Correlations for the overall resistance (f1) and inlet straight duct resistance coefficient (f2) are presented.