Abo Bibliothek: Guest
Digitales Portal Digitale Bibliothek eBooks Zeitschriften Referenzen und Berichte Forschungssammlungen
International Journal of Fluid Mechanics Research
ESCI SJR: 0.22 SNIP: 0.446 CiteScore™: 0.5

ISSN Druckformat: 2152-5102
ISSN Online: 2152-5110

Volumes:
Volumen 46, 2019 Volumen 45, 2018 Volumen 44, 2017 Volumen 43, 2016 Volumen 42, 2015 Volumen 41, 2014 Volumen 40, 2013 Volumen 39, 2012 Volumen 38, 2011 Volumen 37, 2010 Volumen 36, 2009 Volumen 35, 2008 Volumen 34, 2007 Volumen 33, 2006 Volumen 32, 2005 Volumen 31, 2004 Volumen 30, 2003 Volumen 29, 2002 Volumen 28, 2001 Volumen 27, 2000 Volumen 26, 1999 Volumen 25, 1998 Volumen 24, 1997 Volumen 23, 1996 Volumen 22, 1995

International Journal of Fluid Mechanics Research

DOI: 10.1615/InterJFluidMechRes.v29.i6.90
19 pages

Solutions of Polymers under the Conditions of Wall Turbulence. Mechanism of Drag Reduction

Volodymyr G. Pogrebnyak
Donbass State Academy of Building Industry and Architecture, Donetsk, Ukraine
Anatoly A. Pisarenko
Donbass State Academy of Building Industry and Architecture, Donetsk, Ukraine

ABSTRAKT

Results of a polarization-optical investigation of a wall turbulent flow of the solutions of polyethylene oxide (PEO) are presented in the paper. They prove that, within certain zones of the boundary layer, the macromolecules are subjected to a strong deformation effect of the hydrodynamic field. The experimental findings presented in the paper support the idea that the mechanism of drag reduction is uniquely related to the process of strong deformation of the macromolecules, which give rise to the nonlinear effects of elasticity. The adequate experimental verification of unrolling of the molecules under the conditions of wall turbulence illustrates that the employment of non-turbulent flows with stretching for studying the interaction between the macromolecules and the hydrodynamic field has some advantages. This allows an experimental investigation into the "anomalous" effects under the controlled conditions and provides a way of simulating the basic properties of the turbulent boundary layer. The velocity, velocity gradient fields and the degree of the unrolling of the macromolecules in the entry zone of a short capillary (under the modeled conditions of wall turbulence) are studied experimentally. If the flow is converging, the macromolecules are subjected to the considerable unrolling (up to 60 %) under the action of the hydrodynamic field, which leads to reconfiguration of this field. It is found that the behavior of the macromolecules in a flow with a longitudinal velocity gradient along with the effects of elastic deformations, which manifest themselves in this case, are essential for understanding of nature of the "anomalously" low turbulent friction observed in a flow of polymer solutions.


Articles with similar content:

DEFORMATION EFFECTS IN CASE OF A FLOW WITH STRETCHING OF POLYMER SOLUTIONS
Turbulence and Shear Flow Phenomena -1 First International Symposium, Vol.0, 1999, issue
Anatoly A. Pisarenko, Volodymyr G. Pogrebnyak
DEFORMATION EFFECTS IN CASE OF A FLOW WITH STRETCHING OF POLYMER SOLUTIONS
TSFP DIGITAL LIBRARY ONLINE, Vol.1, 1999, issue
Volodymyr G. Pogrebnyak, Anatoly A. Pisarenko
Anomalous heat and mass transport phenomena in drag-reducing turbulence by using surfactant
ICHMT DIGITAL LIBRARY ONLINE, Vol.0, 2018, issue
Yasuo Kawaguchi
Some Aspects of the Wind Action on an Arch-Roof Aeronautical Building
International Journal of Fluid Mechanics Research, Vol.29, 2002, issue 3&4
Adrian Wittwer, Mario De Bortoli, Marlo Natalini
Shear-induced self-diffusion in a Couette flow of a dilute suspension
ICHMT DIGITAL LIBRARY ONLINE, Vol.0, 2009, issue
Evgeny S. Asmolov