The Mass Flow node specifies the mass flow through the boundary. The mass flow is given by the product of the normal velocity vn and the density at the boundary ρbnd. This results in a flux condition given by

Enter the Normal velocity vn (SI unit: m/s) and Fluid density at the boundary ρbnd (SI unit: kg/m3). The defaults are cpf.vref and cpf.rhoref, respectively. The values given in the Reference Values.