Experimental Study of Channel Flow with Porous Walls

2016 ◽  
pp. 149-173
Author(s):  
Shakhbaz A. Yershin
Keyword(s):  
Experimental Study ◽  
Channel Flow ◽  
Porous Walls

scholarly journals 1316 Experimental Study on the Spatial Structure of Drag Reducing Channel Flow with Blowing Polymer Solution from the Wall.

2010 ◽  
Vol 2010 (0) ◽  
pp. 385-386
Author(s):  
Shota Ishitsuka ◽  
Hening Xu ◽  
Masaaki Motozawa ◽  
Kaoru Iwamoto ◽  
Hirotomo Ando ◽  
...  
Keyword(s):  
Experimental Study ◽  
Spatial Structure ◽  
Polymer Solution ◽  
Channel Flow

scholarly journals EXPERIMENTAL STUDY ON THE CHARACTERISTICS OF BRAIDED CHANNEL FLOW

2003 ◽  
Vol 47 ◽  
pp. 445-450
Author(s):  
Nariyasu YOSHIOKA ◽  
Tadashi UTAMI ◽  
Takafumi SUZURI
Keyword(s):  
Experimental Study ◽  
Channel Flow ◽  
Braided Channel

scholarly journals Turbulent channel flow over an anisotropic porous wall – drag increase and reduction

2018 ◽  
Vol 842 ◽  
pp. 381-394 ◽  
Author(s):  
Marco E. Rosti ◽  
Luca Brandt ◽  
Alfredo Pinelli
Keyword(s):  
Drag Reduction ◽  
Channel Flow ◽  
High Speed ◽  
Vertical Direction ◽  
Porous Wall ◽  
Turbulent Channel Flow ◽  
Spanwise Direction ◽  
Normal Velocity ◽  
Porous Walls ◽  
The One

The effect of the variations of the permeability tensor on the close-to-the-wall behaviour of a turbulent channel flow bounded by porous walls is explored using a set of direct numerical simulations. It is found that the total drag can be either reduced or increased by more than 20 % by adjusting the permeability directional properties. Drag reduction is achieved for the case of materials with permeability in the vertical direction lower than the one in the wall-parallel planes. This configuration limits the wall-normal velocity at the interface while promoting an increase of the tangential slip velocity leading to an almost ‘one-component’ turbulence where the low- and high-speed streak coherence is strongly enhanced. On the other hand, strong drag increase is found when high wall-normal and low wall-parallel permeabilities are prescribed. In this condition, the enhancement of the wall-normal fluctuations due to the reduced wall-blocking effect triggers the onset of structures which are strongly correlated in the spanwise direction, a phenomenon observed by other authors in flows over isotropic porous layers or over ribletted walls with large protrusion heights. The use of anisotropic porous walls for drag reduction is particularly attractive since equal gains can be achieved at different Reynolds numbers by rescaling the magnitude of the permeability only.

Heat Transfer in a Laminar Channel Flow Generated by Injection Through Porous Walls

2007 ◽  
Vol 129 (8) ◽  
pp. 1048-1057 ◽  
Author(s):  
Clarisse Fournier ◽  
Marc Michard ◽  
Françoise Bataille
Keyword(s):  
Channel Flow ◽  
Numerical Solutions ◽  
Scaling Law ◽  
Similarity Solutions ◽  
Temperature Profiles ◽  
Governing Equations ◽  
Temperature Boundary ◽  
Laminar Channel Flow ◽  
Porous Walls ◽  
Uniform Fluid

Steady state similarity solutions are computed to determine the temperature profiles in a laminar channel flow driven by uniform fluid injection at one or two porous walls. The temperature boundary conditions are non-symmetric. The numerical solution of the governing equations permit to analyze the influence of the governing parameters, the Reynolds and Péclet numbers. For both geometries, we deduce a scaling law for the boundary layer thickness as a function of the Péclet number. We also compare the numerical solutions with asymptotic expansions in the limit of large Péclet numbers. Finally, for non-symmetric injection, we derive from the computed temperature profile a relationship between the Nusselt and Péclet numbers.

Experimental study on flow drag of flocking pile surface in channel flow

2017 ◽  
Vol 2017.66 (0) ◽  
pp. 418
Author(s):  
Keisuke MOROTOMI ◽  
Zen MATSUMOTO ◽  
Shinji TAMANO ◽  
Toru YAMADA ◽  
Yohei MORINISHI
Keyword(s):  
Experimental Study ◽  
Channel Flow ◽  
Flow Drag
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