Dynamic stability of pipes conveying pulsating fluid

The dynamic stability of supported cylindrical pipes converying fluid, when the flow velocity is harmonically perturbed about a constant mean value, is considered in this paper. Explicit stability conditions for perturbations of small intensity are obtained by using the method of averaging. For large periodic excitation a numerical method based on the Floquet theory is used to extend the stability boundaries. The effects of the mean flow velocity, dissipative forces, boundary conditions, and virtual mass on the extent of the parametric instability regions are then discussed.