Effect of Suspended Sediment on Friction in Polyethylene Pipes

The results of an experimental study on the effect of sediment laden flow on hydraulicresistance in a smooth pipe are presented. The experiments were carried out in two horizontal PE pipe flow systems of 66 and 80 mm in diameter. Flows of volumetric concentrations of 0.1% to 5% and particle diameters of 0.04, 0.064, 0.15, 0.25, 0.72 mm were studied in the experiments. The results are compared with the flow resistance of clear water flow in smooth pipes. These results showed that the presence of suspended sediment in the flow where the Reynolds number is low may increase the head loss up to 125% for an 80 mm smooth pipe. The results also confirm an increase in flow resistance with an increase in volumetric concentration and particle diameter. In some experiments with high Reynolds numbers, sediment transport caused a decrease in pressure drop to less than that of clear water flow. Increasing the Reynolds number may decrease the effect of sediment concentration on head loss so that the number approaches that of clear water flow resistance.