Drag reduction phenomenon with special emphasis on homogeneous polymer solutions

Microrheological effects of drag-reducing polymers in vitro and in vivo

“…Small concentrations of these long-chain polymers were able to reduce flow resistance by up to 80% (Kulicke et al, 1989). To have the drag-reducing property a polymer must have a high molecular weight (MW > 10 6 Da) and a fairly linear flexible structure (Kulicke et al, 1989).…”

“…The major limitation of DRP industrial use was their rapid and irreversible mechanical degradation due to exposure to high shear forces. However, some examples of successful applications of specific (organic) DRP in industry include reducing flow resistance in the 1200 km long Alaskan petroleum pipeline (Kulicke et al, 1989) and in oil-well drilling (Shenoy, 1984). After 65 years of its discovery, the exact mechanism underlying the Toms phenomenon remains incompletely understood.…”

“…Toms discovered that diluted solutions of poly(methyl methacrylate) in monochlorobenzene significantly reduced resistance to the turbulent flow in a pipe (Toms, 1948). This discovery attracted the attention of many specialists in fluid dynamics, physics, and rheology, and was intensively studied in the hope to explain the mechanism(s) of this unique phenomenon and to bring it to practical use, especially, after water soluble polymers such as synthetic polyethylene oxides (Virk, Merrill, Mickley, Smithal, & Mollo-Christensen, 1967), polyacrylamides (Wells & Spangler, 1967), and natural polysaccharides (Kenis, 1968) were found to produce an extraordinary reduction of resistance in turbulent flow (Kulicke, Kotter, & Grager, 1989). It was demonstrated that nanomolar concentrations of soluble long chains polymers characterized by a relatively linear structure, high molecular weight (MW > $10 6 Da) and unique viscoelastic properties were able to significantly increase flow rate at a constant driving pressure or decrease the pressure gradient under a constant flow.…”

Advanced Turbulent Drag Reducing and Flocculating Materials Based on Polysaccharides

“…Despite extensive research ever since its discovery, the mechanism for drag reduction is still eluding satisfactory explanation. The developments in the field have been recently reviewed by Singh 3 , Morgan and McCormic 4 and Kulicke et al 5 As the phenomenon is of great potential benefit to several industrial processes and operations, the search for efficient and shear stable drag-reducing agents is being sustained. However soluble polymers are the most potential drag reducing agents mainly because the drag reducion upto 80% can be obtained by addition of a few tens of the polymer in a particular solvent .…”

Enhanced dispersion by elastic turbulence in porous media

“…The solution was deionized prior to the measurements, as rheological properties of polymer solutions are sensitive to the ion concentration [22]. To avoid aging effects [11], fresh solution was prepared 24 h before each measurement.…”