“…We define the region composed of 0 < r < a, 0 < θ ≤ 2π, and −h < z < η (r, θ, t) as the liquid motion region, φ(r, θ, z, t) as the absolute velocity potential function and ϕ(r, θ, z, t) as the relative velocity potential function. From ∇ 2 ϕ = 0, the kinematics equation and the dynamics equation are obtained, [12] respectively, as follows:…”