【摘要】 以水为工质,对间隙为0.57~3.08mm的水平窄缝环形流道阻力特性进行了实验研究,实验范围包括层流区和紊流区,仔细观察测量了流态转捩点,将实验结果与传统的阻力计算公式进行了对比,分析了流道几何尺寸和偏心度对阻力特性的影响。结果发现,紊流区阻力与普通流道基本相同,但层流区阻力的数值和变化趋势在流道间隙比较小时与理论值之间存在明显差异,流态转捩点也有所提前。更多还原

【Abstract】 Experimental investigations of water flow friction in horizontal narrow annuli, with gap sizes of 0.57-3.08 mm, were carried out. The tests involved both laminar and turbulent flow regimes. The critical Reynolds number transited from laminar flow to turbulent flow was examed and observed. The friction factors obtained from experiments were compared with conventional correlations evaluated results, and the influences of channel scale and eccentricity on flow friction characteristics were discussed. It was found that fluid friction in turbulent regime could be predicted by conventional correlations with satisfied degree, but both values and varying trend of that vs. ri/ro in laminar regime were obviously departure from theoretically results when the gap sizes were less than 2.0 mm, and the critical Reynolds number was slightly less then 2300 when the gap sizes were less than 1.0 mm.更多还原