EFFECT OF DISSIPATION ON LOCAL AND GLOBAL STABILITY OF FLUID-CONVEYING PIPES

This article is focused on the effect of damping on local and global stability of fluid-conveying pipes. Local stability is first considered through the analysis of the dispersion relation for two systems : the fluid conveying pipe on elastic foundation and the tensionned fluid-conveying pipe. The effect of damping is then predicted by calculating the energy of the neutral waves in the system and predictions are drawn regarding stability of the pipe when boundaries are present (finite pipes). Next, numerical computations are presented for finite-length systems and results are compared with predictions. It is finally found that a comparison of lengthscales is enough to know which criterion is able to predict the global stabilty when the non-dimensionnal length 1 >> 1.