Av 1e9[1/m] "Specific area"
T 80[degC] Temperature
p_atm 1[atm] "Ambient pressure"
perm 1e-13[m^2] Permeability
mu 3e-5[Pa*s] Viscosity
k_d 3.16e-8[Pa*m^2/s] "Empirical MS diffusivity expression prefactor"
v_O2 16.6e-6 "Diffusion volume, O2 (Fuller, Schettler, Giddings relation)"
v_H2O 12.7e-6 "Diffusion volume, H2O (Fuller, Schettler, Giddings relation)"
v_N2 17.9e-6 "Diffusion volume, N2 (Fuller, Schettler, Giddings relation)"
M_O2 32[g/mol] "Molar mass, O2"
M_N2 28[g/mol] "Molar mass, N2"
M_H2O 18[g/mol] "Molar mass, H2O"
D_O2N2 k_d*(T[1/K])^1.75/(p_atm*(v_O2^(1/3)+v_N2^(1/3))^2)*(1[kg/mol]/M_O2+1[kg/mol]/M_N2)^0.5 "Maxwell-Stefan diffusivity"
D_O2N2_eff D_O2N2*(eps_gas^1.5) "Effective MS diffusivity"
D_O2H2O k_d*(T[1/K])^1.75/(p_atm*(v_O2^(1/3)+v_H2O^(1/3))^2)*(1[kg/mol]/M_O2+1[kg/mol]/M_H2O)^0.5 "Maxwell-Stefan diffusivity"
D_O2H2O_eff D_O2H2O*(eps_gas^1.5) "Effective MS diffusivity"
D_N2H2O k_d*(T[1/K])^1.75/(p_atm*(v_H2O^(1/3)+v_N2^(1/3))^2)*(1[kg/mol]/M_H2O+1[kg/mol]/M_N2)^0.5 "Maxwell-Stefan diffusivity"
D_N2H2O_eff D_N2H2O*(eps_gas^1.5) "Effective MS diffusivity"
E_cell 0.7[V] "Cell voltage"
Eeq_ref_H2 -(0-(T-25[degC])*131[J/(K*mol)])/(2*F_const) "Reference equilibrium potential, anode"
Eeq_ref_O2 -(-2*229[kJ/mol]-(T-25[degC])*(2*189[J/(K*mol)]-205[J/(K*mol)]))/(4*F_const) "Reference equilibrium potential, cathode"
Eeq_ref Eeq_ref_O2-Eeq_ref_H2 "Cell reference equilibrium potential"
p_vapor 0.61121*exp((18.678-(T-0[degC])/234.5[K])*((T-0[degC])/(257.14+T-0[degC])))[kPa] "Water vapor pressure"
RH 90[%] "Relative humidity"
x_H2O_in RH*p_vapor/p_ref "Inlet water molar fraction"
x_O2_in 0.21*(1-x_H2O_in) "Inlet oxygen molar fraction"
x_H2 RH*p_vapor/p_ref "Hydrogen molar fraction on anode side (assuming the same relative humidity as on cathode side)"
i0_ref_H2 1e4[A/m^2] "Reference exchange current density, anode"
i0_ref_O2 1e-3[A/m^2] "Reference exchange current density, cathode"
alpha_a_H2 0.5 "Transfer coefficient"
alpha_a_O2 3.5 "Transfer coefficient"
p_ref p_atm "Reference pressure"
eps_l 0.3 "Electrolyte volume fraction in porous electrode"
eps_s 0.3 "Electrode volume fraction in porous electrode"
eps_gas 0.4 "Gas phase volume fraction in porous electrode"