3.3.1 Porous Media Conditions (Section 7.2.3)

The first bullet under Limitations and Assumptions of the Porous Media Model should be revised and divided into the following two bullets:

• Since the volume blockage that is physically present is not represented in the model, by default ANSYS FLUENT uses and reports a superficial velocity inside the porous medium, based on the volumetric flow rate, to ensure continuity of the velocity vectors across the porous medium interface. This superficial velocity formulation does not take porosity into account when calculating the convection and diffusion terms of the transport equations. You can choose to use a more accurate alternative, in which the true (physical) velocity is calculated inside the porous medium and porosity is included in the differential terms of the transport equations. See Section 7.2.3: Modeling Porous Media Based on Physical Velocity for details.

• In a multiphase flow system, all phases share the same porosity.

Under Modeling Porous Media Based on Physical Velocity, the second paragraph should be revised to the following:

  The superficial velocity values within the porous region remain the same as those outside of the porous region, and porosity is not taken into account in the differential terms of the transport equations. This limits the accuracy of the porous model in cases where there should be an increase in velocity throughout the porous region, and does not yield accurate results when velocity values and gradients are important. For more accurate simulations of porous media flows, it becomes necessary to solve for the true, or physical, velocity throughout the flowfield rather than the superficial velocity, as well as to include porosity in all terms of the transport equations.