A parametric study to simulate the non‐Newtonian turbulent flow in spiral tubes

Abstract

Abstract Non‐Newtonian fluids are considered to those types of fluids that do not follow Newton's law of viscosity where viscosity would change in either more solid or liquid. The objective of this study, a parametric simulation, was performed to investigate the considerable influence of non‐Newtonian fluids on different parameters on spiral tubes. Firstly, governing equations have derived by computational fluid dynamics methods to compare the laminar and turbulent flows. Then, the turbulent flow, the non‐Newtonian flow, power law flow, and cross models are simulated according to the boundary conditions. Consequently, for the Reynolds range of 600‐2500, increasing the Reynolds number decreases the friction coefficient. It is observed that in slow flow, there is no significant difference between the results of cross and power law models. The distribution of velocity profile has slight variation at the pipe outlet for Reynolds 9000 and 20 000. In other words, the flow is constant in developed region inside the spiral pipe. Moreover, the investigation of pressure drop inside the pipe revealed that regarding the increase in Reynolds number, the friction coefficient decreases. In spiral tubes, due to the presence of secondary currents, the friction coefficient is higher than the direct tube.

Keywords

• computational fluid dynamics
• governing equations
• non‐Newtonian flow
• Reynolds number
• turbulent flow