Evaluating the Effects of Sediment Transport on Pipe Flow Resistance

• Main Authors: Vito Ferro, Alessio Nicosia
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Water
• Subjects: pipe flow; velocity profile; flow resistance; dimensional analysis; self-similarity; sediment transport
• Online Access: https://www.mdpi.com/2073-4441/13/15/2091

In this paper, the applicability of a theoretical flow resistance law to sediment-laden flow in pipes is tested. At first, the incomplete self-similarity (ISS) theory is applied to deduce the velocity profile and the corresponding flow resistance law. Then the available database of measurements carried out by clear water and sediment-laden flows with sediments having a quasi-uniform sediment size and three different values of the mean particle diameter <i>D_m</i> (0.88 mm, 0.41 mm and 0.30 mm) are used to calibrate the Γ parameter of the power-velocity profile. The fitting of the measured local velocity to the power distribution demonstrates that (i) for clear flow the exponent δ can be estimated by the equation of Castaing et al. and (ii) for the sediment-laden flows δ is related to the diameter <i>D_m</i>. A relationship for estimating the parameter Г_v obtained by the power-velocity profile and that Г_f of the flow resistance law is theoretically deduced. The relationship between the parameter Г_v, the head loss per unit length and the pipe flow Froude number is also obtained by the available sediment-laden pipe flow data. Finally, the procedure to estimate the Darcy-Weisbach friction factor is tested by the available measurements.