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 numbe...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.展开更多
In this paper a technique is introduced on visualization of emulsified droplets in gas stream by pulse laser sheet photography. By this technique fairly clear photographs of the concentration and velocity profiles of ...In this paper a technique is introduced on visualization of emulsified droplets in gas stream by pulse laser sheet photography. By this technique fairly clear photographs of the concentration and velocity profiles of water droplets in an activation reactor were obtained. The results of the study show that with a venturi tube installed in the activator, the distribution of the droplets is more uniform than without it; the uniformity of the distribution of the droplets can improve the efficiency of the activation of the sorbent particles in the reactor. The picture of the collision of the droplets was obtained in the experiment, which could be used as basis for the study of the mechanism of humidified activation process. The results of the experimental study of the deposition of the droplets on the reactor walls is also described and discussed.展开更多
文摘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.
文摘In this paper a technique is introduced on visualization of emulsified droplets in gas stream by pulse laser sheet photography. By this technique fairly clear photographs of the concentration and velocity profiles of water droplets in an activation reactor were obtained. The results of the study show that with a venturi tube installed in the activator, the distribution of the droplets is more uniform than without it; the uniformity of the distribution of the droplets can improve the efficiency of the activation of the sorbent particles in the reactor. The picture of the collision of the droplets was obtained in the experiment, which could be used as basis for the study of the mechanism of humidified activation process. The results of the experimental study of the deposition of the droplets on the reactor walls is also described and discussed.
