scholarly journals Uncertainty and Sensitivity Analysis in Turbulent Pipe Flow Simulation

2021 ◽  
Author(s):  
Z. Ding ◽  
K. Truffin ◽  
S. Jay ◽  
D. Sinoquet
Keyword(s):  
Sensitivity Analysis ◽  
Pipe Flow ◽  
Flow Simulation ◽  
Turbulent Pipe Flow ◽  
Uncertainty And Sensitivity Analysis

Fluid Transmission Line Modeling Using a Variational Method

1998 ◽  
Vol 122 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Jari Ma¨kinen ◽  
Robert Piche´ ◽  
Asko Ellman
Keyword(s):  
Differential Equations ◽  
Variational Method ◽  
Ordinary Differential Equations ◽  
Transmission Lines ◽  
Pipe Flow ◽  
Transient Flow ◽  
Numerical Models ◽  
Flow Simulation ◽  
Gibbs Phenomenon ◽  
Turbulent Pipe Flow

A variational method is used to derive numerical models for transient flow simulation in fluid transmission lines. These are generalizations of models derived using the more traditional modal method. Three different transient compressible laminar pipe flow models are considered (inviscous, one-dimensional linear viscous, and two-dimensional dissipative viscous flow), and a model for transient turbulent pipe flow is given. The (model) equations in the laminar case are given in the form of a set of constant coefficient ordinary differential equations, and for the turbulent case (model) in the form of a set of nonlinear ordinary differential equations. Explicit equations are given for various end conditions. Attenuation factors, similar to the window functions used in spectral analysis, are used to attenuate Gibbs phenomenon oscillations. [S0022-0434(00)03201-9]

Structural organization of large and very large scales in turbulent pipe flow simulation

2013 ◽  
Vol 720 ◽  
pp. 236-279 ◽  
Author(s):  
J. R. Baltzer ◽  
R. J. Adrian ◽  
Xiaohua Wu
Keyword(s):  
Turbulent Flows ◽  
Pipe Flow ◽  
Velocity Fluctuation ◽  
Large Scale ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Streamwise Velocity ◽  
Turbulent Pipe Flow ◽  
Low Velocity ◽  
Logarithmic Layer

AbstractThe physical structures of velocity are examined from a recent direct numerical simulation of fully developed incompressible turbulent pipe flow (Wu, Baltzer & Adrian, J. Fluid Mech., vol. 698, 2012, pp. 235–281) at a Reynolds number of ${\mathit{Re}}_{D} = 24\hspace{0.167em} 580$ (based on bulk velocity) and a Kármán number of ${R}^{+ } = 685$. In that work, the periodic domain length of $30$ pipe radii $R$ was found to be sufficient to examine long motions of negative streamwise velocity fluctuation that are commonly observed in wall-bounded turbulent flows and correspond to the large fractions of energy present at very long streamwise wavelengths (${\geq }3R$). In this paper we study how long motions are composed of smaller motions. We characterize the spatial arrangements of very large-scale motions (VLSMs) extending through the logarithmic layer and above, and we find that they possess dominant helix angles (azimuthal inclinations relative to streamwise) that are revealed by two- and three-dimensional two-point spatial correlations of velocity. The correlations also reveal that the shorter, large-scale motions (LSMs) that concatenate to comprise the VLSMs are themselves more streamwise aligned. We show that the largest VLSMs possess a form similar to roll cells centred above the logarithmic layer and that they appear to play an important role in organizing the flow, while themselves contributing only a minor fraction of the flow turbulent kinetic energy. The roll cell motions play an important role with the smaller scales of motion that are necessary to create the strong streamwise streaks of low-velocity fluctuation that characterize the flow.

Particle Destabilization in Turbulent Pipe Flow

1989 ◽  
Vol 21 (6-7) ◽  
pp. 435-442 ◽  
Author(s):  
B. Döll
Keyword(s):  
Pipe Flow ◽  
Reaction Rate ◽  
Turbulent Pipe Flow ◽  
Cationic Polymers ◽  
Flow Conditions ◽  
Polyelectrolyte Adsorption ◽  
Charge Neutralization ◽  
Silica Suspensions ◽  
Kinetics Of ◽  
Turbulent Flow Conditions

Silica suspensions (pH = 6.8) and three different cationic polymers were used to study the kinetics of charge neutralization by polyelectrolyte adsorption. The experiments were performed in a continuous flow pipe reactor under steady state turbulent flow conditions. The charge neutralization was monitored by electrophoretic mobility (EPM) measurements of the suspended particles as a function of time after polyelectrolyte audition. The results show the dependency of the destabilization reaction rate on flow and polymer characteristics.

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