$A$	permeability coefficient of water through the corresponding membrane (m·s−1·Pa−1)
$a$	effective membrane surface area for solution passage (m2)
$B$	permeability coefficient of inorganic salt (m·s−1)
D	diffusion coefficient (m2·s−1)
δ	boundary layer thickness (m)
$C_{\mathrm{m}}$	concentration of the inorganic salt on the feed side of the membrane (kg·m−3)
$C_{\mathrm{p}}$	concentration of the inorganic salt on the permeate side of the membrane (kg·m−3)
K	mass transfer coefficient
$J$	permeate flux, (m3·m−2·s−1)
$J_{\mathrm{s}}$	salt flux (kg·m−2·s−1)
$\mu$	fluid viscosity (kg·m−1·s−1)
$\mathsf{\Delta }P$	pressure difference across both sides of the membrane (Pa)
$\mathsf{\Delta }\Pi$	osmotic pressure difference across both sides of the membrane (Pa)
$p$	pressure (Pa)
$\rho$	fluid density (kg·m−3)
S	source term
$u$	fluid velocity vector (m·s−1)
$V$	corresponding effective computational domain volume (m3)
$v$	flow velocity (m·s−1) (u is the vector)