I modeled fully developed fluid flow through curved pipe filled with porous media . I want to know the friction factor near the walls. I wonder about the effect of porous media on friction factor? I personally think that, the presence of porous media must affect friction factor near the wall and makes it higher than normal one. Another question is what is the effect of porous media on pressure difference near walls?
thank you
Dear Amirhosein Bashiri,
if I understood well your question; this mathematical developments are found in fluid flow mechanics in discontinuous media and in the process of drag reduction phenomenon. There are plenty of books in the oil (petroleum) field dealing with this type of modelling. Regards
At high Reynolds numbers (high turbulence levels), the flow in porous media is dominated by inertial forces and ‘‘wall roughness,’’ as in pipe flow. The porous medium can be considered an ‘‘extremely rough’’ conduit. Thus, the flow at a sufficiently high Reynolds number should be fully turbulent and the friction factor should be constant. The effect of porous media can be see through The Burke - Plummer equation or Ergun Equation that can be used for evaluation of friction factor in porous media. to relate wall effect and pressure difference
Shear Stress at wall = (∆P R) / 2L and
friction factor = shear stress / density . velocity^2
Dear Amirhossein,
We have investigated some effects of porous media in terms of pressure drop and heat transfer enhancement in an annulus in a paper entitled " Numerical investigation of flow characteristics, heat transfer and entropy generation of nanofluid flow inside an annular pipe partially or completely filled with porous media using two-phase mixture model" published by Energy and is available in my profile.
Best wishes
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