SINUSOIDAL EXCITATION OF VISCOUS FLUIDS IN PIPES

The concept of applying a prescribed oscillation to viscous fluids to aid or increase flow is examined. Application of this technique to flu ids presents unique problems such as physical separation; control of h eat and mass transfer in certain industrial applications; and improvem ent of some fluid process methods. The problem as stated is to obtain the velocity distribution, wall shear stress and energy expended when a pipe containing a stagnant viscous fluid is externally excited by a sinusoidal pulse, one end of the pipe being pinned. On the other hand, the effect of different parameters on the results are presented. Such parameters include fluid viscosity, frequency of oscillations and pip e geometry. It was' found that the flow velocity is maximum at the pip e wall, and it decreases rapidly towards the pipe centerline. The freq uency of oscillation should be above a certain value in order to obtai n meaningful flow velocity. The amount of energy absorbed in the syste m is mainly due to pipe wall strain energy, and the fluid pressure and kinetic energies are comparatively small. (C) 1997 Elsevier Science L td.