Development of local turbulent drag reduction due to nonuniform polymer concentration

1979 ◽  
Vol 22 (1) ◽  
pp. 183 ◽  
Author(s):  
W. D. McComb ◽  
L. H. Rabie
Keyword(s):  
Drag Reduction ◽  
Polymer Concentration ◽  
Turbulent Drag Reduction ◽  
Turbulent Drag

Experimental Study on Turbulent Drag Reduction and Polymer Concentration Distribution With Blowing Polymer Solution From the Channel Wall

2010 ◽  
Author(s):  
Masaaki Motozawa ◽  
Taiki Kurosawa ◽  
Hening Xu ◽  
Kaoru Iwamoto ◽  
Hirotomo Ando ◽  
...  
Keyword(s):  
Experimental Study ◽  
Drag Reduction ◽  
Polymer Solution ◽  
Concentration Distribution ◽  
Channel Wall ◽  
Polymer Concentration ◽  
Channel Height ◽  
Wall Region ◽  
Turbulent Drag Reduction ◽  
Turbulent Drag

Experimental study on turbulent drag reduction (DR) and polymer concentration distribution with blowing polymer solution from whole surface of the channel wall was carried out. A set of measurements for drag reduction were performed with blowing rate for the sintered porous metal plate (0.45m × 0.45m × 3) adjusted from 0.5 L/min to 4.0 L/min, and concentration of polymer solution varied from 10 ppm to 200 ppm. Reynolds number based on the channel height was chosen for 20000 and 40000 in this experiment. The polymer concentration distribution in the near-wall region (0.5 mm < y < 20 mm) at three locations of the downstream from the leading edge of the blower wall was also measured. Polymer concentration can be analyzed via Total Organic Carbon (TOC) analyzer. Through the analysis of mass transfer by polymer concentration distribution, we found that polymer which exists in buffer layer (10 < y+ < 70) has important influence on drag reduction.

Turbulent drag reduction characteristics of amylopectin and its derivative

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Sung Taek Lim ◽  
Hyoung Jin Choi ◽  
Diptirani Biswal ◽  
Ram Prakash Singh
Keyword(s):  
Drag Reduction ◽  
Polymer Concentration ◽  
Rotating Disk ◽  
Turbulent Drag Reduction ◽  
Experimental Conditions ◽  
Shear Stability ◽  
Turbulent Drag ◽  
Strong Shear ◽  
Shaft Torque ◽  
Reduction Characteristics

Abstract Using amylopectin (AP) and a derivative, we systematically investigated their turbulent drag reduction characteristics and shear stability. The expected shear stability of polysaccharides as drag reducing and flocculating agents triggered our study on structural modification of AP. For this purpose, we prepared a derivative of AP, viz. AP grafted with polyacrylamide (GA), in which the granular form of AP powder (≈10 μm) changed into a mixture of larger fibrils and lumps. Using a rotating-disk apparatus, we measured the shaft torque and calculated the turbulent drag reduction (DR) efficiency under various experimental conditions, i.e., different polymer concentration, rotation speed, and temperature. Contrary to AP, GA showed relatively high DR efficiencies (27%) and very strong shear resistance.

scholarly journals Fibre-induced drag reduction

2008 ◽  
Vol 602 ◽  
pp. 209-218 ◽  
Author(s):  
J. J. J. GILLISSEN ◽  
B. J. BOERSMA ◽  
P. H. MORTENSEN ◽  
H. I. ANDERSSON
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Drag Reduction ◽  
Elastic Layer ◽  
Turbulent Drag Reduction ◽  
Rigid Polymer ◽  
Fibre Concentration ◽  
Induced Drag ◽  
Turbulent Drag

We use direct numerical simulation to study turbulent drag reduction by rigid polymer additives, referred to as fibres. The simulations agree with experimental data from the literature in terms of friction factor dependence on Reynolds number and fibre concentration. An expression for drag reduction is derived by adopting the concept of the elastic layer.

scholarly journals Turbulent drag reduction in a dilute polymeric solution flowing through a fiber-implanted circular pipe.

1988 ◽  
Vol 21 (4) ◽  
pp. 441-443
Author(s):  
HIROTSUGU HATTORI ◽  
TOMOO YAMAUCHI ◽  
SEIICHI TANABE ◽  
HIDEOMI MATSUDA
Keyword(s):  
Drag Reduction ◽  
Circular Pipe ◽  
Turbulent Drag Reduction ◽  
Polymeric Solution ◽  
Turbulent Drag

Turbulent drag reduction by spanwise oscillations of a ribbed surface

2013 ◽  
Vol 48 (4) ◽  
pp. 461-470 ◽  
Author(s):  
I. S. Vodop’yanov ◽  
N. V. Nikitin ◽  
S. I. Chernyshenko
Keyword(s):  
Drag Reduction ◽  
Turbulent Drag Reduction ◽  
Turbulent Drag
Sign in / Sign up

Export Citation Format

Share Document