小尺度环形通道流体阻力特性实验研究

为确定小尺度环形流道间隙尺寸对流体阻力特性的影响,以水为工质,分别在滞流区和湍流区对间隙为0.540～2.685 mm的水平环形通道单相流体摩擦阻力特性进行实验研究。结果表明,小尺度环形通道的流体阻力特性与理论分析有明显的差异。摩擦系数随环形流道间隙的减小而减小,且流态转捩点较常规尺寸提前。当环形通道间隙大于2.5 mm时流体的流动特性符合常规尺寸的特性。依据实验结果,给出了窄缝环形通道的流体阻力预测式。

Experimental Investigation of Flow Resistance Characteristics in Small Scale Annuli

Experimental investigations of water flow friction in horizontal annuli, with gap sizes of 0.540～2.685 mm, were carried out to determine the effect of gap sizes on the flow resistance characteristics, and the test involved the laminar and turbulent flow regimes. The results showed that of the characteristics of the fluid friction resistance of small scale annuli were obviously different with the theoretical results. The critical Reynolds number in small-scale annuli was slightly less than in normal size annul, but when the gap size is above 2.5 mm, flow resistance characteristics accord with normal size annuli. The flow resistance coef-ficient formula of narrow annuli were established based on the experiment results.