Laminar flow in a tube subject to sinusoidal oscillations

摘要

The hydrodynamic laminar flow of an incompressible Newtonian fluid in the entrance region of a horizontal tube oscillating around a vertical diameter has been calculated numerically. This problem is governed by three parameters : the through-flowReynolds number, an oscillations' Reynolds number and the oscillations' amplitude. Typical results show the existence of a periodic secondary transverse flow, a large increase of the friction factor and the existence of an 'oscillating fully developed'flow region. The increase of the tube oscillations' amplitude intensifies the secondary flow. It also causes increasing variations of the axial velocity and of the friction factor which is significantly higher than the corresponding values for astationary tube.