ρ ρ ( ∂ ∂ u ∂ ∂ t + ( u ⋅ ⋅ ∇ ∇ ) u ) = − − ∇ ∇ p + ∇ ∇ ⋅ ⋅ { μ μ [ ∇ ∇ u + ( ∇ ∇ u ) T − − 2 3 ( ∇ ∇ ⋅ ⋅ u ) I ] } + ∇ ∇ [ ζ ζ ( ∇ ∇ ⋅ ⋅ u ) ] + ρ ρ f − − ρ ρ [ 2 Ω Ω × × u + Ω Ω × × ( Ω Ω × × x ) + d U d t + d Ω Ω d t × × x ] .