Hello All,
I'm new to porous media simulations. I'm trying to create a pressure drop using porous media. I plotted the velocity vs dP/L and curved fitted using the equation Ax^2+Bx. I used A as inertial resistance and B as viscous resistance. My viscous resistance value is one order of magnitude less than the inertial resistance. Kindly let me know if this trend is acceptable, I heard from some that the viscous resistance should always be higher than the inertial resistance. I can provide more info if needed. Thank you.
Dear Bharath Ram Ravi,
The ratio of inertial to viscous resistance in a porous media depends for a STEADY flow (constant pressure difference imposed across the medium) on the Reynolds number Re defined as: Re=U d/nu. U is a characteristic flow velocity (filter velocity), d is a typical pore diameter and nu is the kinematic viscosity (dynamic viscosity divided by density) of the fluid. For an imposed harmonic unsteady pressure difference with frequency f one should consider the ratio of unsteady inertial force and viscous forces ( 2 pi f U)/(nu U/d^2)=(2 pi f d^2)/nu, where pi=3.14... Hence the answer depends on the characteristic flow conditions you are considering. These are best described in terms of dimensionless numbers. Regards, Mico
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