NUMERICAL SIMULATION OF HYDRODYNAMICAL BEHAVIOUR OF SAND WATER MIXTURES

摘要

Modern Trailer Suction Hopper Dredgers are capable of dredging material upto a density of 1700kg/m~3. These high density mixtures lead to new challenges. Examples of these challenges are higher load stresses and wear of components like bends, valves or dredge pumps. An accurate prediction of the velocity and sediment distribution is essential to tackle the above mentioned issues. In order to predict the velocity and sediment distribution an extensive numerical model has been made. The sand water mixture is modeled as a continuum. The model solves the Navier-Stokes equations numerically using the fractional step method. Transport equations, in combination with a closure relation and the flow, are used to calculate the sediment distribution. An example of a closure relation is the Richardson and Zaki equation. The equations are discretized using the Finite Volume Method with a collocated scheme. The results from a one dimensional sedimentation experiment are compared with the numerical results from the model. The agreement is good.