A head loss model for slurry transport in the heterogeneous regime

Although sophisticated 2 and 3 layer models exist for slurry flow (here the flow of sand/gravel water mixtures), the main Dutch and Belgium dredging companies still use modified Durand and Condolios (1952) and Fuhrboter (1961) models, while the main companies in the USA use a modified Wilson et al. (1992) model for heterogeneous transport. These older models use one term for the excess pressure losses, the pressure losses resulting from the solids, with an empirical character. A new model has been developed based on energy considerations. The model consists of two terms for the excess pressure losses, one for the potential energy losses and one for the kinetic energy losses. This gives more flexibility matching experimental results. Although the model is derived fundamentally, the slip velocity of the particles is still an unknown in the model. An equation for this slip velocity is derived, based on physical parameters. The resulting model is validated with numerous experimental data from the literature and from the Delft Dredging Laboratory and matches very well. The advantage of this model is, that it requires the parameters known to the dredging industry and is thus easy to use.