| 摘要: |
| 试验表明,薄塑软管中的水流流态属光滑管紊流,它与一般塑料硬管在输水性能上的差别是:水流断面可随工作压力变化,因此其沿程水头损失和沿程阻力系数不仅取决于雷诺数,与其流量和直径有关,同时还受管首工作压力的影响。分析提出了薄塑软管断面呈全圆形时,管首工作压力一定和变动下的沿程水头损失及沿程阻力系数的经验公式。经验证,符合应用要求。 |
| 关键词: 低压管灌系统,薄塑软管,光滑管紊流,沿程水头损失,沿程阻力系数 |
| DOI： |
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| Experiments of Frictional Head Loss for Polyvinyl Plastic Hose Changed in Nature |
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Lin Xincui Fan Zhisheng
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| Abstract: |
| Experiments indicate that the flow state in polyvinyl plastic hose belongs to the turbulent flow in the smooth tube, whose differences from the general plastic rigid hose in water delivery capability are that the corss section of water flow changes with the service pressure. Therefore, the frictional head loss and frictional resistant coefficients not only depend on Reynold's nubers but also relate to discharge and diameter, being affected by pipe service pressure. It is suggested through analysis that when the cross section of plastic hose appears to be circular in shape, empirical equations of frictional head loss and frictional resistant coefficient are established. Through the tests, these equations can well meet the requirements of practical application. |
| Key words: irrigation system with low pressure, thin plastic hose, turbulent flow in the smooth tube, frictional head loss, frictional resistant coefficient |
