The Peculiarities of the Structure of Wall Turbulence and the Mechanism of Drag Reduction by Polymer Additives

1985 ◽  
pp. 101-106
Author(s):  
L. I. Sedov ◽  
V. A. Ioselevich ◽  
V. N. Pilipenko
Keyword(s):  
Drag Reduction ◽  
Wall Turbulence ◽  
Polymer Additives

scholarly journals Actuation response model from sparse data for wall turbulence drag reduction

2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Daniel Fernex ◽  
Richard Semaan ◽  
Marian Albers ◽  
Pascal S. Meysonnat ◽  
Wolfgang Schröder ◽  
...  
Keyword(s):  
Drag Reduction ◽  
Sparse Data ◽  
Wall Turbulence ◽  
Response Model

scholarly journals Global effect of local skin friction drag reduction in spatially developing turbulent boundary layer

2016 ◽  
Vol 805 ◽  
pp. 303-321 ◽  
Author(s):  
A. Stroh ◽  
Y. Hasegawa ◽  
P. Schlatter ◽  
B. Frohnapfel
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Drag Reduction ◽  
Control Region ◽  
Reduction Rate ◽  
Wall Turbulence ◽  
Local Skin ◽  
Control Schemes ◽  
Local Skin Friction ◽  
Friction Drag Reduction

A numerical investigation of two locally applied drag-reducing control schemes is carried out in the configuration of a spatially developing turbulent boundary layer (TBL). One control is designed to damp near-wall turbulence and the other induces constant mass flux in the wall-normal direction. Both control schemes yield similar local drag reduction rates within the control region. However, the flow development downstream of the control significantly differs: persistent drag reduction is found for the uniform blowing case, whereas drag increase is found for the turbulence damping case. In order to account for this difference, the formulation of a global drag reduction rate is suggested. It represents the reduction of the streamwise force exerted by the fluid on a plate of finite length. Furthermore, it is shown that the far-downstream development of the TBL after the control region can be described by a single quantity, namely a streamwise shift of the uncontrolled boundary layer, i.e. a changed virtual origin. Based on this result, a simple model is developed that allows the local drag reduction rate to be related to the global one without the need to conduct expensive simulations or measurements far downstream of the control region.

A drag reduction in cwm transportation with polymer additives

KSME Journal ◽  
1991 ◽  
Vol 5 (1) ◽  
pp. 53-58
Author(s):  
Seon Chang Kim ◽  
Chong Bo Kim
Keyword(s):  
Drag Reduction ◽  
Polymer Additives

Electrochemical methods in the study of the hydrodynamic drag reduction by high polymer additives

1975 ◽  
Vol 20 (11) ◽  
pp. 909-911 ◽  
Author(s):  
C. Deslouis ◽  
I. Epelboin ◽  
B. Tribollet ◽  
L. Viet
Keyword(s):  
Drag Reduction ◽  
Electrochemical Methods ◽  
Hydrodynamic Drag ◽  
Polymer Additives ◽  
High Polymer
Sign in / Sign up

Export Citation Format

Share Document