International Journal of Dynamics of Fluids

The incompressible viscous steady flow through a helical pipe of circular cross-section rotating at a constant angular velocity about the center of curvature is investigated numerically to examine the combined effects of rotation (Coriolis force), torsion and curvature (centrifugal force) on the flow. The flow depends on the Taylor number , the Deannumber and the dimensionless curvature of the duct δ, where a is the radius of the helical pipe, Ω_T the angular velocity, μ the viscosity, ν the kinematic viscosity, G the constant pressure gradient along the pipe axis and β₀ a parameter related to the torsion τ and curvature δ. When Ω_T > 0, the rotation is in the direction as the Coriolis force enforces the curvature effect. When Ω_T < 0, the rotation is in the direction as the Coriolis force exhibits an opposite effect to that of curvature. The calculations are carried out for −500 ≤ T_r ≤ 500, D_n = 500, 0 < δ ≤ 1.2 and 0 ≤β₀ ≤ 1.2. The trajectories of fluid particles are calculated for δ= 2.0 at β₀ = 0.4 and 1.2. These trajectories reveal complicated mixing of the fluid particle.