scholarly journals POD analysis of oscillating grid turbulence in water and shear thinning polymer solution

AIChE Journal ◽  
2020 ◽  
Vol 67 (1) ◽  
Author(s):  
Tom Lacassagne ◽  
Serge Simoëns ◽  
Mahmoud EL Hajem ◽  
Jean‐Yves Champagne
Keyword(s):  
Polymer Solution ◽  
Shear Thinning ◽  
Grid Turbulence ◽  
Pod Analysis ◽  
Oscillating Grid

Experimental Study on the Drag-Reducing Characteristics in Two-Oscillating Grid Turbulence With Polymer Additives

2016 ◽  
Author(s):  
Yue Wang ◽  
Weihua Cai ◽  
Tong-zhou Wei ◽  
Feng-chen Li ◽  
Li-ming Yao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Kinetic Energy ◽  
Drag Reduction ◽  
Polymer Solution ◽  
Turbulent Kinetic Energy ◽  
Newtonian Fluid ◽  
Reduction Rate ◽  
Grid Turbulence ◽  
Solution Flow ◽  
Oscillating Grid

In this paper, we carried out the experimental study to investigate the polymer effect on two-oscillating grid turbulence based on Particle Image Velocimetry. We chose five different concentrations (25, 50, 100, 150 and 200ppm) of polymer solution flow and the Newtonian fluid flow for comparison at three different grid oscillating frequencies (5, 7.5 and 10Hz). The results showed that comparison with the Newtonian fluid case, the turbulent kinetic energy is much smaller in polymer solution cases. A natural definition for drag reduction rate was proposed based on turbulent kinetic energy. It showed that the maximum drag reduction reaches around 80% and the drag-reducing effect increases as the concentration increases. Finally, proper orthogonal decomposition (POD) was used to extract coherent structures in grid turbulence.

scholarly journals Oscillating grid turbulence in shear-thinning polymer solutions

2019 ◽  
Vol 31 (8) ◽  
pp. 083102 ◽  
Author(s):  
T. Lacassagne ◽  
S. Simoëns ◽  
M. EL Hajem ◽  
A. Lyon ◽  
J.-Y. Champagne
Keyword(s):  
Polymer Solutions ◽  
Shear Thinning ◽  
Grid Turbulence ◽  
Oscillating Grid

scholarly journals Flow around an oscillating grid in water and shear-thinning polymer solution at low Reynolds number

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Tom Lacassagne ◽  
Adrien Lyon ◽  
Serge Simoëns ◽  
Mahmoud El Hajem ◽  
Jean-Yves Champagne
Keyword(s):  
Liquid Phase ◽  
Turbulence Intensity ◽  
Oscillatory Flow ◽  
Shear Thinning ◽  
Grid Turbulence ◽  
Mean Flow ◽  
Dilute Polymer Solutions ◽  
Reynolds Decomposition ◽  
Turbulence Production ◽  
Oscillating Grid

Abstract The study of turbulence in complex fluids is of great interest in many environmental and industrial applications, in which the interactions between liquid phase rheology, turbulence, and other phenomena such as mixing or heat and mass transfer have to be understood. Oscillating grid stirred tanks have been used for many purposes in research involving turbulence. However, the mechanisms of turbulence production by the oscillating grid itself have never been studied, and oscillating grid turbulence (OGT) remained undescribed in non-Newtonian, shear-thinning, dilute polymer solutions until recently (Lacassagne et al., in Phys Fluids 31(8):083,102, 2019). The aim of this paper is to study the influence of the shear-thinning property of dilute polymer solutions (DPS), such as xanthan gum (XG), on mean flow, oscillatory flows, and turbulence around an oscillating grid. Liquid phase velocity is measured by particle image velocimetry (PIV) in a vertical plane above the central grid bar. Mean, oscillatory and turbulent components of the velocity fields are deduced by triple Hussain–Reynolds decomposition based on grid phase-resolved measurements. Outside of the grid swept region, the amplitude of oscillatory fluctuations quickly become negligible compared to that of turbulent fluctuations, and the triple and classical Reynolds decomposition become equivalent. Oscillatory jets and wakes behind the grid and their interactions are visualized. Turbulent (Reynolds) and oscillatory stresses are used to evidence a modification of oscillatory flow and turbulence intensity repartition in and around the grid swept region. Energy transfer terms between mean, oscillatory and turbulent flows are estimated and used to describe turbulence production in the grid swept region. Energy is injected by the grid into the oscillatory component. In water, it is transferred to turbulence mostly inside the grid swept region. In DPS, oscillatory flow persists outside of the grid swept zone. Energy is transferred not only to turbulence , in the grid swept region, and far from the tank’s walls, but also to the mean flow, leading to an enhancement of the latter. Mean flow production and enhancement mechanisms are explainable by oscillatory jet variable symmetry and intensity, and by time- and space-variable viscosity. Backward transfer from turbulence to oscillatory flow is also evidenced in DPS. Finally, using phased root mean square (rms) values of turbulent velocity fluctuations, it is shown that in water, the decay of turbulence intensity behind an oscillating grid can be related to the decay of fixed grid turbulence for specific grid positions, a result no longer valid in DPS. Graphic abstract

On POD analysis of PIV measurements applied to mixing in a stirred vessel with a shear thinning fluid

2013 ◽  
Vol 91 (11) ◽  
pp. 2073-2083 ◽  
Author(s):  
A. Liné ◽  
J.-C. Gabelle ◽  
J. Morchain ◽  
D. Anne-Archard ◽  
F. Augier
Keyword(s):  
Shear Thinning ◽  
Piv Measurements ◽  
Stirred Vessel ◽  
Pod Analysis ◽  
Shear Thinning Fluid

Temperature Dependence of the Shear-Thinning Behavior o Partially Hydrolyzed Polyacrylamide Solution for Enhanced Oil Recovery

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Pan-Sang Kang ◽  
Jong-Se Lim ◽  
Chun Huh
Keyword(s):  
Temperature Dependence ◽  
Polymer Solution ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Polymer Concentration ◽  
Shear Thinning ◽  
Temperature Model ◽  
Polyacrylamide Solution ◽  
Partially Hydrolyzed Polyacrylamide ◽  
Hydrolyzed Polyacrylamide

Abstract The viscosity of injection fluid is a critical parameter that should be considered for the design and evaluation of polymer flood, which is an effective and popular technique for enhanced oil recovery (EOR). It is known that the shear-thinning behavior of EOR polymer solutions is affected by temperature. In this study, temperature dependence (25–70 °C) of the viscosity of a partially hydrolyzed polyacrylamide solution, the most widely used EOR polymer for oil field applications, was measured under varying conditions of the polymer solution (polymer concentration: 500–3000 ppm, NaCl salinity: 1000–10,000 ppm). Under all conditions of the polymer solution, it was observed that the viscosity decreases with increasing temperature. The degree of temperature dependence, however, varies with the conditions of the polymer solution. Martin model and Lee correlations were used to estimate the dependence of the viscosity of the polymer solution on the polymer concentration and salinity. In this study, we proposed a new empirical model to better elucidate the temperature dependence of intrinsic viscosity. Analysis of the measured viscosities shows that the accuracy of the proposed temperature model is higher than that of the existing temperature model.

230 Experimental study of rotation effect on vortex structure in oscillating-grid turbulence

2016 ◽  
Vol 2016.65 (0) ◽  
pp. _230-1_-_230-2_
Author(s):  
Masaki MIZUOCHI ◽  
Mitsuhiro KIMURA ◽  
Shinji TAMANO ◽  
Yohei MORINISHI
Keyword(s):  
Experimental Study ◽  
Vortex Structure ◽  
Grid Turbulence ◽  
Rotation Effect ◽  
Oscillating Grid
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