STUDY OF THE BEHAVIOURS OF SINGLE-PHASE TURBULENT FLOW AT LOW TO MODERATE REYNOLDS NUMBERS THROUGH A VERTICAL PIPE. PART I: 2D COUNTERS ANALYSIS

• Published in: Eureka, Physics and Engineering (Online) Physics and Engineering (Online), 2020 (6), p.108-122
• Main Authors: Morad, Akeel M Ali, Qasim, Rafi M., Ali, Amjed Ahmed
• Format: Article
• Language: English
• Subjects: Energy consumption; Energy dissipation; Fluid dynamics; Fluid flow; Incompressible flow; Kinetic energy; Laminar flow; Laminar mixing; Numerical models; Pipes; Reynolds number; Shear forces; Shear walls; Static pressure; Turbulence; Turbulent flow; Two dimensional analysis; Two dimensional models; Velocity; Velocity distribution; Wall flow
• ISSN: 2461-4254; 2461-4262
• DOI: 10.21303/2461-4262.2020.001538

This study presents a model to investigate the behavior of the single-phase turbulent flow at low to moderate Reynolds number of water through the vertical pipe through (2D) contour analysis. The model constructed based on governing equations of an incompressible Reynolds Average Navier-Stokes (RANS) model with (k-ε) method to observe the parametric determinations such as velocity profile, static pressure profile, turbulent kinetic energy consumption, and turbulence shear wall flows. The water is used with three velocities values obtained of (0.087, 0.105, and 0.123 m/s) to represent turbulent flow under low to moderate Reynolds number of the pipe geometry of (1 m) length with a (50.8 mm) inner diameter. The water motion behavior inside the pipe shows by using [COMSOL Multiphysics 5.4 and FLUENT 16.1] Software. It is concluded that the single-phase laminar flow of a low velocity, but obtained a higher shearing force; while the turbulent flow of higher fluid velocity but obtained the rate of dissipation of shearing force is lower than that for laminar flow. The entrance mixing length is affected directly with pattern of fluid flow. At any increasing in fluid velocity, the entrance mixing length is increase too, due to of fluid kinetic viscosity changes. The results presented the trends of parametric determinations variation through the (2D) counters analysis of the numerical model. When fluid velocity increased, the shearing force affected directly on the layer near-wall pipe. This leads to static pressure decreases with an increase in fluid velocities. While the momentum changed could be played interaction rules between the fluid layers near the wall pipe with inner pipe wall. Finally, the agreement between present results with the previous study of [1] is satisfied with the trend