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Core and Fuel Assembly Fluid Flow
Published in Robert E. Masterson, Nuclear Reactor Thermal Hydraulics, 2019
where RCF is the roughness correction factor. In general, the RCF is not a simple function, and it depends on many parameters including the Reynolds number. If the average surface roughness is ε, then increases in the friction factor can be correlated to the ratio ε/D, which is called the relative roughness. In this case, the relative roughness is the dimensionless quantity that is used in the Moody charts. For transitional flow and turbulent flow in circular pipes, the friction factor can be correlated to the relative roughness and the Reynolds number by a relationship called the Colebrook equation, which is expressed as
Fluid Mechanics
Published in Yeong Koo Yeo, Chemical Engineering Computation with MATLAB®, 2020
5.8 Water is flowing through a horizontal 1 in. schedule 40 steel pipe at 1 atm and 25°C. The inside diameter and the length of the pipe are 0.0266m and 20m, respectively, and the roughness factor is 0.00005m. The pressure drop in the pipe is equal to 118kPa. The density of water is 1000kg/m3 and the viscosity is 0.001kg/(m∙sec). Determine the inlet volumetric flow rate of water. The friction factor can be obtained from the Colebrook equation.
An easy MS Excel software to use for water distribution system design: A real case distribution network design solution
Published in Journal of Applied Water Engineering and Research, 2020
Headloss in a pipe is calculated by Darcy–Weisbach equation as follows: where hf is the headloss in the pipe (m water column) due to friction, Q is the flowrate in the pipe (m³/s), g is the gravitational acceleration (9.81 m/s²), D is the diameter of the pipe (m), L is the length of the pipe (m), and λ is the friction factor. The friction factor is calculated iteratively by Colebrook equation as follows: where e is the roughness height of the pipe (m), and Re is the Reynolds number. Reynolds number in a pipe is calculated by the following formula: where ρ is the density of water (kg/m³), and µ is the dynamic viscosity of water (kg/m.s).
Pickup rate of non-cohesive sediments in low-velocity flows
Published in Journal of Hydraulic Research, 2022
Dake Chen, Bruce Melville, Jinhai Zheng, Yigang Wang, Chi Zhang, Dawei Guan, Cheng Chen
The shear stresses and could be calculated by the Darcy equation: where is shear stress; is the density of water; is the average velocity of duct flow, which can be obtained from the measured flow rate; and is the friction factor, which can be obtained from the Colebrook equation: where is roughness height; is hydraulic diameter, defined by , in which is the flow area and is the wetted perimeter; is Reynolds number, defined by , with being kinematic viscosity of water. The roughness height of the wall () equals 0.025 mm. The roughness height of the sediment sample () is taken to be equal to half of the sediment diameter, following the recommendation of Briaud et al. (2001). This is because the top half of a particle in the surface of the sample protrudes into the duct flow, whereas the bottom half is buried in the sediment mass when the top surface of the sand sample is kept flush with the bottom of the duct during the test.
Oil pipeline hydraulic resistance coefficient identification
Published in Cogent Engineering, 2021
Timur Bekibayev, Uzak Zhapbasbayev, Gaukhar Ramazanova, Daniyar Bossinov
The application of the Colebrook equation has difficulties in the hydraulic calculations of the pipelines. Brkić (2011) performed a review of the existing explicit approximations and constructed an algorithm for calculating the Colebrook equation. It has been shown that most of the available approximations of the Colebrook formula (including the Altshul’s formula) are accurate with a difference of a few percent.