L 0.02[m] "Cell length"
H_ch 1e-3[m] "Channel height"
W_ch 0.7874e-3[m] "Channel width"
W_rib 0.90932e-3[m] "Rib width"
H_gdl 380e-6[m] "GDL width"
H_electrode 50e-6[m] "Porous electrode thickness"
H_membrane 100e-6[m] "Membrane thickness"
eps_gas_gdl 0.4 "GDL gas pore volume fraction (porosity)"
eps_l_cl 0.3 "Catalyst layer electrolyte (ionomer) volume fraction"
eps_gas_cl 0.3 "Catalyst layer gas pore volume fraction"
kappa_gdl 1.18e-11[m^2] "GDL permeability"
kappa_cl kappa_gdl/5 "Catalyst layer permeability"
sigma_gdl 222[S/m] "GDL electric conductivity"
sigma_m 9.825[S/m] "Membrane conductivity"
T 180+273.15[K] "Cell temperature"
p_ref 1[atm] "Reference pressure"
V_cell 0.95[V] "Cell voltage"
i0_ref_c 1e-3[A/m^2] "Reference exchange current density, cathode"
i0_ref_a 1e2[A/m^2] "Reference exchange current density, anode"
alpha_c 1 "Transfer coefficient, cathode"
Av 1e7[m^2/m^3] "Specific surface area"
T_hum 28[degC] "Humidification temperature"
p_vapor 0.61121*exp((18.678-(T_hum-0[degC])/234.5[K])*((T_hum-0[degC])/(257.14+T_hum-0[degC])))[kPa] "Water partial pressure"
x_H2O_in p_vapor/p_ref "Inlet water molar fraction"
x_H2_in 1-x_H2O_in "Inlet hydrogen molar fraction"
x_O2_in 0.21*(1-x_H2O_in) "Inlet oxygen molar fraction"
I_stoich 1[A/cm^2]*L*(W_rib+W_ch) "Operating current for gas flow calculations"
lambda_anode 1.2 "Anode stoichiometry"
lambda_cathode 2 "Cathode stoichiometry"
U_in_anode lambda_anode*I_stoich/(2*F_const)*(R_const*T)/p_ref/x_H2_in/(H_ch*W_ch) "Inlet velocity, anode"
U_in_cathode lambda_cathode*I_stoich/(4*F_const)*(R_const*T)/p_ref/x_O2_in/(H_ch*W_ch) "Inlet velocity, cathode"