DarcyBasisVelocity

Define the reference velocity of the porous material with index $Material$: The law of Darcy models the influence of a porous medium A on a fluid B that flows through A by the addition of a momentum source term to the standard fluid flow equations of B. See EquationsToSolve for the integration of this source term to the momentum equation and TwoPhaseDarcy for a more specific example of using Darcy within MESHFREE. The magnitude and direction of this source term is dependent on the relative velocity between A and B. Therefore the DarcyBasisVelocity should be defined as a projection of the velocity of the porous medium to the points of the fluid. The function projY() can be used to project a MESHFREE-entity %ind_Entity% from the porous medium to the fluid (and vice versa).