...Based on the Lowest Equal-Order Elements for the Stokes...
Then, Equation (26) is established. Analogously, an auxiliary problem in the porous media domain is introduced: find Φ ∈ H 1 ( Ω p ) such that − ∇ · ( K ∇ Φ ) = 0 in Ω p , K ∇ Φ · n p = ρ g v h