我已经对你感到十分着迷,必须向你揭晓,你是何许人也。——奥斯卡·王尔德,The Picture of Dorian Grey那时候的台北没有像现在那么多的高楼,上课不专心时目光闲闲朝窗外瞟去,老树油墨墨的密叶静静晃动,犹如呼吸般吐纳着规律节奏。...我已经对你感到十分着迷,必须向你揭晓,你是何许人也。——奥斯卡·王尔德,The Picture of Dorian Grey那时候的台北没有像现在那么多的高楼,上课不专心时目光闲闲朝窗外瞟去,老树油墨墨的密叶静静晃动,犹如呼吸般吐纳着规律节奏。衬底的天空总是那么干净,即便是阴雨的日子,那种灰也仍是带着透明的润泽。几朵乌云睡姿慵懒,隔一会儿便翻动一下身子,舒展一下筋骨。展开更多
Many factors such as outer diameter, hub ratio, blade numbers, shape and stagger angle affect the performance of small cooling fans. A small cooling fan was simulated using CFD software for three blade stagger angles ...Many factors such as outer diameter, hub ratio, blade numbers, shape and stagger angle affect the performance of small cooling fans. A small cooling fan was simulated using CFD software for three blade stagger angles （30.5°, 37.5°, 44.5°）and obtained the internal flow field and the static characteristics. Research indicated that the stagger angle has an obvious effect on the static characteristics of a fan. For flow rates below 0.0104 mVs, total pressure is the greatest when the stagger angle is 37.5°; flow rates higher than 0.0104 m^3/s, the total pressure is greatest when the stagger angle is 44.5° For the same flow rates, the velocity at inlet of pressure surface increases with in- creasing stagger angle, but the change of velocity on the suction surface is very small. For one model, vortices and the speed of revolution surfaces decrease with tip clearance increasing. But for other three models, increasing the stagger angle, the vortex intensity and speed of revolution surfaces at same height tip clearance increases, simultaneously, the position of vortex offset from the top of the rotor blade to the suction surface.展开更多
文摘我已经对你感到十分着迷,必须向你揭晓,你是何许人也。——奥斯卡·王尔德,The Picture of Dorian Grey那时候的台北没有像现在那么多的高楼,上课不专心时目光闲闲朝窗外瞟去,老树油墨墨的密叶静静晃动,犹如呼吸般吐纳着规律节奏。衬底的天空总是那么干净,即便是阴雨的日子,那种灰也仍是带着透明的润泽。几朵乌云睡姿慵懒,隔一会儿便翻动一下身子,舒展一下筋骨。
基金support of Zhejiang Provincial Natural Science Foundation (No.R107635)Zhejiang Provincial Key Science Foundation (2008 C11027)National Natural Science Foundation of China (No.50735004)
文摘Many factors such as outer diameter, hub ratio, blade numbers, shape and stagger angle affect the performance of small cooling fans. A small cooling fan was simulated using CFD software for three blade stagger angles （30.5°, 37.5°, 44.5°）and obtained the internal flow field and the static characteristics. Research indicated that the stagger angle has an obvious effect on the static characteristics of a fan. For flow rates below 0.0104 mVs, total pressure is the greatest when the stagger angle is 37.5°; flow rates higher than 0.0104 m^3/s, the total pressure is greatest when the stagger angle is 44.5° For the same flow rates, the velocity at inlet of pressure surface increases with in- creasing stagger angle, but the change of velocity on the suction surface is very small. For one model, vortices and the speed of revolution surfaces decrease with tip clearance increasing. But for other three models, increasing the stagger angle, the vortex intensity and speed of revolution surfaces at same height tip clearance increases, simultaneously, the position of vortex offset from the top of the rotor blade to the suction surface.
