r : ∂ ∂ u r ∂ ∂ t + u r ∂ ∂ u r ∂ ∂ r + u ϕ ϕ r ∂ ∂ u r ∂ ∂ ϕ ϕ + u z ∂ ∂ u r ∂ ∂ z − − u ϕ ϕ 2 r = − − 1 ρ ρ ∂ ∂ P ∂ ∂ r + 1 r ρ ρ ∂ ∂ ( r τ τ r r ) ∂ ∂ r + 1 r ρ ρ ∂ ∂ τ τ ϕ ϕ r ∂ ∂ ϕ ϕ + 1 ρ ρ ∂ ∂ τ τ z r ∂ ∂ z − − τ τ ϕ ϕ ϕ ϕ r ρ ρ + f r ϕ ϕ : ∂ ∂ u ϕ ϕ ∂ ∂ t + u r ∂ ∂ u ϕ ϕ ∂ ∂ r + u ϕ ϕ r ∂ ∂ u ϕ ϕ ∂ ∂ ϕ ϕ + u z ∂ ∂ u ϕ ϕ ∂ ∂ z + u r u ϕ ϕ r = − − 1 r ρ ρ ∂ ∂ P ∂ ∂ ϕ ϕ + 1 r ρ ρ ∂ ∂ τ τ ϕ ϕ ϕ ϕ ∂ ∂ ϕ ϕ + 1 r 2 ρ ρ ∂ ∂ ( r 2 τ τ r ϕ ϕ ) ∂ ∂ r + 1 ρ ρ ∂ ∂ τ τ z ϕ ϕ ∂ ∂ z + f ϕ ϕ z : ∂ ∂ u z ∂ ∂ t + u r ∂ ∂ u z ∂ ∂ r + u ϕ ϕ r ∂ ∂ u z ∂ ∂ ϕ ϕ + u z ∂ ∂ u z ∂ ∂ z = − − 1 ρ ρ ∂ ∂ P ∂ ∂ z + 1 ρ ρ ∂ ∂ τ τ z z ∂ ∂ z + 1 r ρ ρ ∂ ∂ τ τ ϕ ϕ z ∂ ∂ ϕ ϕ + 1 r ρ ρ ∂ ∂ ( r τ τ r z ) ∂ ∂ r + f z