7.6.15.21.1. Bkw_Mmp

Syntax: Pressure [{of} SpeciesName] = Bkw_Mmp [Covol = covol | R = r]
Scope: Aria Material
Summary: Computes a spatially varying local pore pressure at nucleation/pore sites. This pressure is computed using the BKW EOS and incorporates chemical decomposition, reaction nucleation and elastic volumetric thermal expansion. Once this local pore pressure exceeds a critical pressure, the chemical material becomes permeable.
Description: Computes the pressure from the BKW EOS, evaluated as $p =\frac{z\rho R T}{MW_g}$ . Here, $R$ is the gas constant, $T$ is temperature and $MW_g$ is the molecular weight of the gas species. $z$ is evaluated as $z = (1+x\exp(0.298 x))$ , with x computed as $x=\frac{\rho_{pg}0.0105V_{co}}{MW_g\sqrt{(T + 6620.0)}}$ . $\rho_{pg}$ is the PORE GAS DENSITY, and $V_{co}$ is the covolume.