The model is calibrated with three coefficients. The magnitude of rapid redeposition flow and its concentration depend on mixing effects that are proportional to the ratio particle settling velocity and the mixture velocity squared. Centrifugal advection can be determined by identifying the onset of radial outflow at the disc near the cutter ring. Centrifugal advection and rapid redeposition spillage are considered the two most significant spillage types out of the six classified. It is hypothesized that the pressure difference over the discs drives an inflow at the disc closest to the nose. The axial pump effect is governed by the mixture velocity at the suction mouth. This allows for the derivation of a pressure-discharge affinity law from the Navier-Stokes. For the centrifugal pump effect, and centrifugal pump effect only, the flow inside the cutter is considered steady, non-gravitational, inviscid and non-axial.

A triad of forces governs flow in the cutter head for typical cutting conditions: a centrifugal, suction and gravitational force are considered.

Prediction accuracy of 5 percentage point is achieved with a two-disc potential flow model complemented with empirical closing relationships. This thesis presents the Sand-Rock Cutting Spillage Model (SRCSM), an engineering model that is particle size-agnostic and makes use of cutting parameters that are all available to the dredge operator. As of yet, no analytical model exists in literature that can estimate spillage rates for a given set of cutting parameters. In addition to higher energy consumption and material wear for delivering the targeted depth, spillage can lead to a variety of environmental issues. Werkhoven, Jeroen (TU Delft Mechanical, Maritime and Materials Engineering)ĬSD spillage is defined as “any soil that is dislodged above the lowest cutter tip trajectory of a single swing, but is not sucked into the suction pipe”. CSD Spillage Model for Sand and Rock: A Particle Size-Agnostic, Adaptable Engineering Model for the Prediction of Cutter Suction Dredge Spillage Rates

Dredge operator definition