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PorePressureFlux Command

The PorePressureFlux command applies pore fluid volum fraction fluxes to surfaces near particles (which are expected to be on the surface) in MPM calculations. It applies a flux to all particles within the shape for a ParticleBC block.

PorePressureFlux (mode),(face),(style),(value),<(timeOrRes)>

where the parameters depend on the type of pore pressure flux being applied. The two types of flux boundary conditions, which depend on (mode), are as follows.

Externally Applied Pore Pressure Flux

This condition applies a surface flux in pore fluid volume fraction/((length units)^2-sec). A positive value is flux into the material while a negative value is flux out of the material. The parameters are:

Coupled Pore Pressure Flux

This version calculates the pore volume fraction flux from a function of the difference between the particle pore pressure and an entered bath pressure. The parameters are:

Note that because t is used for particle concentration, a couple surface flux function cannot depend on time.