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以蒸馏水为实验工质,用紫铜管和PVC管组成间隙尺寸为0.540～2.685 mm的窄环形流道中,对雷诺数在200～6 000的5组窄环形通道内的流体阻力特性进行了实验研究。结果表明:与圆管相比,窄环形通道内流体流动出现了从层流向湍流过渡提前的现象,且流态的转捩雷诺数随着窄环隙尺寸的减小而减小。常规环形通道与窄环形通道的临界间隙尺寸约为2.5 mm,间隙小于2.5 mm的窄环形通道的摩擦阻力系数值随着环隙尺寸的增大而增大。
Taking distilled water as experimental working medium, the fluid resistance characteristics of 5 sets of narrow annular channels with Reynolds number of 200-6000 were tested in a narrow annular flow channel with gap size of 0.540-2.685 mm, which was made of copper pipe and PVC pipe the study. The results show that compared with the circular tube, the flow in the narrow annular channel leads to the transition from laminar to turbulent flow ahead of time, and the Reynolds number of the turbulent flow decreases with the decrease of the narrow annular gap. The critical gap size between conventional annular channel and narrow annular channel is about 2.5 mm, and the frictional resistance coefficient of narrow annular channel with gap less than 2.5 mm increases with the increase of annular gap size.