Pipe flow

About: Pipe flow is a research topic. Over the lifetime, 13826 publications have been published within this topic receiving 351605 citations.

Fine-tuning of the backward erosion piping model through small-scale, medium-scale and IJkdijk experiments

Abstract: A semi-theoretical model is available to estimate the effect of backward erosion piping by underseepage in a dike by computing the critical head. The model accounts for the groundwater flow through the subsoil, pipe flow through the erosion channel and a limited particle equilibrium at the bottom of the channel. This model is extended and updated with the results of a wide range of tests presented in the paper of (Van Beek et al., 2011). The small- scale tests are analyzed by means of a multivariate regression in order to identify the level of influence of each variable. The regression outcome for the permeability corresponds precisely with the outcome of the prediction rule. The effect of relative density, uniformity and particle roundness is empirically dealt with. The role of the particle size is adapted in the new empirical formulation.

Computation of energy dissipation in transient flow

Abstract: A new model for the computation of unsteady friction losses in transient flow is developed and verified in this study. The energy dissipation in transient flow is estimated from the instantaneous velocity profiles. The ratio of the energy dissipation at any instant and the energy dissipation obtained by assuming quasi-steady conditions defines the energy dissipation factor. This is a nondimensional, time-varying parameter that modifies the friction term in the transient flow governing equations. The model was verified for laminar and turbulent flows and the comparison of measured and computed pressure heads shows excellent agreement. This model can be adapted to an existing transient program that uses the well-known method of characteristics for the solution of the continuity and momentum equations.