Fully Developed Turbulent Flow in a Concentric Annulus11

Purpose The purpose of this paper is to solve Navier–Stokes equations including the effects of temperature and inner pipe rotation for fully developed turbulent flow in eccentric annuli by using finite difference scheme with fixing non-linear terms. Design/methodology/approach A mathematical model is proposed for fully developed turbulent flow including the effects of temperature and inner pipe rotation in eccentric annuli. Obtained equation is solved numerically via central difference approximation. In this process, the non-linear term is frozen. In so doing, the non-linear equation can be considered as a linear one. Findings The convergence analysis is studied before using the method to the proposed momentum equation. It reflects that the method approaches to the exact solution of the equation. The numerical solution of the mathematical model shows that pressure gradient can be predicted with a good accuracy when it is compared with experimental data collected from experiments conducted at Izmir Katip Celebi University Flow Loop. Originality/value The originality of this work is that Navier–Stokes equations including temperature and inner pipe rotation effects for fully developed turbulent flow in eccentric annuli are solved numerically by a finite difference method with frozen non-linear terms.

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Assessment of Different Turbulence Models in Helically Coiled Pipes Through Comparison With Experimental Data

Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles ◽

10.1115/icone20-power2012-54546 ◽

2012 ◽

Cited By ~ 1

Author(s):

Marco Colombo ◽

Antonio Cammi ◽

Marco E. Ricotti

Keyword(s):

Turbulent Flow ◽

Great Influence ◽

Turbulence Models ◽

Reynolds Stress Model ◽

Test Facility ◽

Wall Functions ◽

Pressure Drops ◽

Fully Developed Turbulent Flow ◽

Computational Fluid Dynamics Cfd ◽

Helical Geometry

This paper deals with a comprehensive study of fully developed single-phase turbulent flow and pressure drops in helically coiled channels. To the aim, experimental pressure drops were measured in an experimental campaign conducted at SIET labs, in Piacenza, Italy, in a test facility simulating the Steam Generator (SG) of a Generation III+ integral reactor. Very good agreement is found between data and some of the most common correlations available in literature. Also more data available in literature are considered for comparison. Experimental results are used to assess the results of Computational Fluid Dynamics (CFD) simulations. By means of the commercial CFD package FLUENT, different turbulence models are tested, in particular the Standard, RNG and realizable k-ε models, Shear Stress Transport (SST) k-ω model and second order Reynolds Stress Model (RSM). Moreover, particular attention is placed on the different types of wall functions utilized through the simulations, since they seem to have a great influence on the calculated results. The results aim to be a contribution to the assessment of the capability of turbulence models to simulate fully developed turbulent flow and pressure drops in helical geometry.

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Turbulent Flow in Axially Rotating Pipes

Journal of Fluids Engineering ◽

10.1115/1.3240633 ◽

1980 ◽

Vol 102 (1) ◽

pp. 97-103 ◽

Cited By ~ 54

Author(s):

Mitsukiyo Murakami ◽

Kouji Kikuyama

Keyword(s):

Velocity Profile ◽

Turbulent Flow ◽

Flow Pattern ◽

Axial Velocity ◽

Hydraulic Loss ◽

Pressure Distributions ◽

Axial Velocity Profile ◽

Fully Developed Turbulent Flow ◽

Smooth Pipe ◽

Pipe Rotation

Experimental results concerning the flow pattern and hydraulic resistance in a rotating pipe are described. A fully developed turbulent flow was introduced into a long smooth pipe rotating about its axis, and changes of the flow pattern, together with hydraulic loss within the pipe, were examined by measuring the velocity and pressure distributions across sections at various distance from the pipe entrance. Increase of pipe rotation continuously reduces the hydraulic loss and gradually changes the axial velocity profile from a turbulent type to a laminar one. Governing factors for these changes are discussed.

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