Flexible and rigid long chain polymers in very dilute solutions can significantly reduce the drag in turbulent flows. The polymers successively stretch and coil by interacting with the turbulent structures, which changes the turbulent flow and further imposes a transient behavior on the drag reduction (DR) as well as a subsequent mechanical polymer degradation. This time-dependent phenomenon is strongly affected by a number of parameters, which are analyzed here, such as the Reynolds number, polymer concentration, polymer molecular weight, and salt concentration. This last parameter can dramatically modify the polymeric structure. The investigation of the salt concentration's impact on the DR is mostly motivated by some potential applications of this technique to ocean transport and saline fluid flows. In the present paper, a cylindrical double gap rheometer device is used to study the effects of salt concentration on DR over time. The reduction of drag is induced by three polymers: poly (ethylene oxide) (PEO), polyacrylamide (PAM), and xanthan gum (XG). These polymers are dissolved in deionized water both in the presence of salt and in its absence. The DR is displayed from the very start of the test to the time when the DR achieves its final level of efficiency, following the mechanical degradations. The presence of salt in PEO and XG solutions reduces the maximum DR, DRmax, as well as the time to achieve it. In contrast, the DR does not significantly change over the time for PAM solutions upon the addition of salt.

References

References
1.
Forrest
,
F.
, and
Grierson
,
G. A.
,
1931
, “
Friction Losses in Cast Iron Pipe Carrying Paper Stock
,”
Pap. Trade J.
,
92
(
22
), pp.
39
41
.
2.
Toms
,
B. A.
,
1948
, “
Some Observations on the Flow of Linear Polymer Solutions Through Straight Tubes at Large Reynolds Numbers
,” International Congress of Rheology, Holland, North-Holland, Amsterdam, Section II, pp.
135
141
.
3.
Mysels
,
K. J.
,
1949
, “
Flow of Thickened Fluids
,” U.S. Patent No. 2,492,173.
4.
Sellin
,
R. H. J.
,
Hoyt
,
J. W.
,
Poliert
,
J.
, and
Scrivener
,
O.
,
1982
, “
The Effect of Drag Reducing Additives on Fluid Flows and There Industrial Applications Part II: Present Applications and Futures Proposals
,”
J. Hydraul. Res.
,
20
(
3
), pp.
235
292
.
5.
Burger
,
E. D.
, and
Chorn
,
L. G.
,
1980
, “
Studies of Drag Reduction Conducted Over a Broad Range of Pipeline Conditions When Flowing Prudhoe Bay Crude Oil
,”
J. Rheol.
,
24
(
5
), pp.
603
626
.
6.
Fabula
,
A. G.
,
1971
, “
Fire-Fighting Benefits of Polymeric Friction Reduction
,”
Trans. ASME J. Basic Eng.
,
93
(
3
), pp.
453
455
.
7.
Figueredo
,
R. C. R.
, and
Sabadini
,
E.
,
2003
, “
Firefighting Foam Stability: The Effect of the Drag Reducer Poly(ethylene) Oxide
,”
Colloids Surf., A
,
215
(
1–3
), pp.
77
86
.
8.
Golda
,
J.
,
1986
, “
Hydraulic Transport of Coal in Pipes With Drag Reducing Additives
,”
Chem. Eng. Commun.
,
43
(
1–3
), pp.
53
67
.
9.
Greene
,
H. L.
,
Mostardi
,
R. F.
, and
Nokes
,
R. F.
,
1980
, “
Effects of Drag Reducing Polymers on Initiation of Atherosclerosis
,”
Polym. Eng. Sci.
,
20
(
7
), pp.
499
504
.
10.
Shah
,
S. N.
, and
Zhou
,
Y.
,
2009
, “
Maximum Drag Reduction Asymptote of Polymeric Fluid Flow in Coiled Tubing
,”
ASME J. Fluids Eng.
,
131
(
1
), p.
011201
.
11.
Kamel
,
A. H.
, and
Shah
,
S. N.
,
2013
, “
Maximum Drag Reduction Asymptote for Surfactant-Based Fluids in Circular Coiled Tubing
,”
ASME J. Fluids Eng.
,
135
(
3
), p.
031201
.
12.
Virk
,
P. S.
,
Merril
,
E. W.
,
Mickley
,
H. S.
, and
Smith
,
K. A.
,
1967
, “
The Toms Phenomenon: Turbulent Pipe Flow of Dilute Polymer Solutions
,”
J. Fluid Mech.
,
30
(
2
), pp.
305
328
.
13.
Hershey
,
H. C.
, and
Zakin
,
J. L.
,
1967
, “
A Molecular Approach to Predicting the Onset of Drag Reduction in the Turbulent Flow of Dilute Polymer Solutions
,”
Chem. Eng. Sci.
,
22
(
12
), pp.
1847
1857
.
14.
Virk
,
P. S.
,
Mickley
,
H. S.
, and
Smith
,
K. A.
,
1970
, “
The Ultimate Asymptote and Mean Flow Structure in Toms Phenomenon
,”
ASME J. Appl. Mech.
,
37
(
2
), pp.
488
493
.
15.
Paterson
,
R. W.
, and
Abernathy
,
F.
,
1970
, “
Turbulent Flow Drag Reduction and Degradation With Dilute Polymer Solutions
,”
J. Fluid Mech.
,
43
(
4
), pp.
689
710
.
16.
Virk
,
P. S.
,
1975
, “
Drag Reduction Fundamentals
,”
AIChE J.
,
21
(
4
), pp.
625
656
.
17.
Bewersdorff
,
H. W.
,
1982
, “
Effect of a Centrally Injected Polymer Thread on Drag in Pipe Flow
,”
Rheol. Acta
,
21
(
4–5
), pp.
587
589
.
18.
Moussa
,
T.
, and
Tiu
,
C.
,
1994
, “
Factors Affecting Polymer Degradation in Turbulent Pipe Flow
,”
Chem. Eng. Sci.
,
49
(
10
), pp.
1681
1692
.
19.
Gyr
,
A.
, and
Tsinober
,
T.
,
1995
, “
On the Rheological Nature of Drag Reduction Phenomena
,”
J. Non-Newtonian Fluid Mech.
,
73
(
1–2
), pp.
153
162
.
20.
Kalashnikov
,
V. N.
,
1998
, “
Dynamical Similarity and Dimensionless Relations for Turbulent Drag Reduction by Polymer Additives
,”
J. Non-Newtonian Fluid Mech.
,
75
(
2–3
), pp.
209
230
.
21.
Bewersdorff
,
H. W.
, and
Berman
,
N. S.
,
1988
, “
The Influence of Flow-Induced Non-Newtonian Fluid Properties on Turbulent Drag Reduction
,”
Rheol. Acta
,
27
(
2
), pp.
130
136
.
22.
White
,
C. M.
, and
Mungal
,
M. G.
,
2008
, “
Mechanics and Prediction of Turbulent Drag Reduction With Polymer Additives
,”
Annu. Rev. Fluid Mech.
,
40
(
1
), pp.
235
256
.
23.
Lumley
,
J. L.
,
1969
, “
Drag Reduction by Additives
,”
Annu. Rev. Fluid Mech.
,
11
(
1
), pp.
367
384
.
24.
Seyer
,
F. A.
, and
Metzner
,
A. B.
,
1969
, “
Turbulence Phenomena in Drag Reducing Systems
,”
AIChE J.
,
15
(
3
), pp.
426
434
.
25.
Ryskin
,
G.
,
1987
, “
Turbulent Drag Reduction by Polymers: A Quantitative Theory
,”
Phys. Rev. Lett.
,
59
(
18
), pp.
2059
2062
.
26.
Tabor
,
M.
, and
de Gennes
,
P. G.
,
1986
, “
A Cascade Theory of Drag Reduction
,”
Europhys. Lett.
,
2
(
7
), pp.
519
522
.
27.
Joseph
,
D. D.
,
1990
,
Fluid Dynamics of Viscoelastic Liquids
,
Springer Verlag
,
New York
.
28.
Dimitropoulos
,
C. D.
,
Dubief
,
Y.
,
Shaqfeh
,
E. S. G.
,
Moin
,
P.
, and
Lele
,
S. K.
,
2005
, “
Direct Numerical Simulation of Polymer-Induced Drag Reduction in Turbulent Boundary Layer Flow
,”
Phys. Fluids
,
17
(
1
), pp.
1
4
.
29.
Pereira
,
A. S.
, and
Soares
,
E. J.
,
2012
, “
Polymer Degradation of Dilute Solutions in Turbulent Drag Reducing Flows in a Cylindrical Double Gap Rheometer Device
,”
J. Non-Newtonian Fluid Mech.
,
179
, pp.
9
22
.
30.
Pereira
,
A. S.
,
Andrade
,
R. M.
, and
Soares
,
E. J.
,
2013
, “
Drag Reduction Induced by Flexible and Rigid Molecules in a Turbulent Flow Into a Rotating Cylindrical Double Gap Device: Comparison Between Poly(ethylene oxide), Polyacrylamide, and Xanthan Gum
,”
J. Non-Newtonian Fluid Mech.
,
202
, pp.
72
87
.
31.
Andrade
,
R. M.
,
Pereira
,
A. S.
, and
Soares
,
E. J.
,
2014
, “
Drag Increase at the Very Start of Drag Reducing Flows in a Rotating Cylindrical Double Gap Device
,”
J. Non-Newtonian Fluid Mech.
,
212
, pp.
73
79
.
32.
Peyser
,
P.
, and
Little
,
R. C.
,
1971
, “
The Drag Reduction of Dilute Polymer Solutions as a Function of Solvent Power, Viscosity, and Temperature
,”
J. Appl. Polym. Sci.
,
15
(
11
), pp.
2623
2637
.
33.
Harrington
,
R. E.
, and
Zimm
,
B. H.
,
1965
, “
Degradation of Polymers by Controlled Hydrodynamic Shear
,”
J. Phys. Chem.
,
69
(
1
), pp.
161
175
.
34.
Nakano
,
A.
, and
Minoura
,
Y.
,
1975
, “
Relationship Between Hydrodynamic Volume and the Scission of Polymer Chains by High-Speed Stirring in Several Solvents
,”
Macromolecules
,
8
(
5
), pp.
677
680
.
35.
Zakin
,
J. L.
, and
Hunston
,
D. L.
,
1978
, “
Effects of Solvent Nature on the Mechanical Degradation of High Polymer Solutions
,”
J. Appl. Polym. Sci.
,
22
(
6
), pp.
1763
1766
.
36.
Choi
,
H. J.
,
Kim
,
C. A.
,
Sohn
,
J.
, and
Jhon
,
M. S.
,
2000
, “
An Exponential Decay Function for Polymer Degradation in Turbulent Drag Reduction
,”
Polym. Degrad. Stab.
,
69
(
3
), pp.
341
346
.
37.
Virk
,
P. S.
,
1975
, “
Drag Reduction by Collapsed and Extended Polyelectrolytes
,”
Nature
,
253
(
5487
), pp.
109
110
.
38.
Morris
,
E. R.
,
1977
, “
Molecular Origin of Xanthan Solution Properties
,”
Extracellular Microbial Polysaccharides
(
ACS Symposium Series
, Vol.
45
),
American Chemical Society
,
Washington, DC
, pp.
81
89
.
39.
Norton
, I
. T.
,
Goodall
,
D. M.
,
Frangou
,
S. A.
,
Morris
,
E. R.
, and
Ress
,
D. A.
,
1984
, “
Mechanism and Dynamics of Conformational Ordering in Xanthan Polysaccharide
,”
J. Mol. Biol.
,
175
(
3
), pp.
371
394
.
40.
Muller
,
G.
,
Anrhourrache
,
M.
,
Lecourtier
,
J.
, and
Chauveteau
,
G.
,
1986
, “
Salt Dependence of the Conformation of a Single-Stranded Xanthan
,”
Int. J. Biol. Macromol.
,
8
(
3
), pp.
167
172
.
41.
Bewersdorff
,
H. W.
, and
Singh
,
R. P.
,
1988
, “
Rheological and Drag Reduction Characteristics of Xanthan Gum Solutions
,”
Rheol. Acta
,
27
(
6
), pp.
617
627
.
42.
Kamel
,
A.
, and
Shah
,
S. N.
,
2009
, “
Effects of Salinity and Temperature on Drag Reduction Characteristics of Polymers in Straight Circular Pipes
,”
J. Pet. Sci. Eng.
,
67
(
1–2
), pp.
23
33
.
43.
Elbing
,
B. R.
,
Winkel
,
E. S.
,
Solomon
,
M. J.
, and
Ceccio
,
S. L.
,
2009
, “
Degradation of Homogeneous Polymer Solutions in High Shear Turbulent Pipe Flow
,”
Exp. Fluids
,
47
(
6
), pp.
1033
1044
.
44.
Kwon
,
D. H.
,
2002
, “
Salt and Clay Effect on Drag Reduction Efficiency of Polyethyleneoxide in Turbulent Flow
,” Ph.D. thesis,
Department of Polymer Science & Engineering, Inha University
,
Inchon, Korea
.
45.
Little
,
R. C.
,
1973
, “
Effect of Salt Concentration on the Drag Reduction Efficiency of Polyethylene Oxide Polymers
,”
Nature
,
242
(
118
), pp.
79
80
.
46.
Chen
,
P.
,
Yao
,
L.
,
Liu
,
Y.
,
Luo
,
J.
,
Zhou
,
G.
, and
Jiang
,
B.
,
2012
, “
Experimental and Theoretical Study of Dilute Polyacrylamide Solutions: Effect of Salt Concentration
,”
J. Mol. Model.
,
18
(
7
), pp.
3153
3160
.
47.
Shetty
,
A. M.
, and
Solomon
,
M. J.
,
2009
, “
Aggregation in Dilute Solutions of High Molar Mass Poly(ethylene) Oxide and Its Effect on Polymer Turbulent Drag Reduction
,”
Polymer
,
50
(
1
), pp.
261
270
.
48.
Whitcomb
,
P. J.
, and
Macosko
,
C. W.
,
1978
, “
Rheology of Xanthan Gum
,”
J. Rheol.
,
22
(
5
), pp.
493
505
.
49.
Rochefort
,
W.
, and
Middleman
,
S.
,
1987
, “
Rheology of Xanthan Gum: Salt, Temperature, and Strain Effects in Oscillatory and Steady Shear Experiments
,”
J. Rheol.
,
31
(
4
), pp.
337
369
.
50.
Virk
,
P. S.
,
Sherman
,
D. C.
, and
Wagger
,
D. L.
,
1997
, “
Additive Equivalence During Turbulent Drag Reduction
,”
AIChE J.
,
43
(
12
), pp.
3257
3259
.
You do not currently have access to this content.