Binliang Lin

Numerical modelling of three-dimensional suspended sediment for estuarine and coastal waters

Details are given herein of the development and application of a three-dimensional layer-integrated model to predict suspended sediment fluxes in estuarine and coastal waters. The model involves using the finite difference technique to solve the equations of mass and momentum conservation and the transport equation for suspended sediment. The operator splitting technique and a highly accurate finite difference scheme have been used to solve the suspended sediment transport equation. The model has been tested against analytical solutions and laboratory measurements for different flow types and boundary conditions, and has also been applied to predict suspended sediment fluxes in the Humber Estuary, UK.

Numerical modelling of solute transport in compound channel flows

A 3-D numerical model has been developed to investigate transport processes of solute in a compound open channel. The Navier-Stokes equations have been numerically solved in conjunction with the linear and nonlinear k-∊ models to predict flow fields and turbulent parameters. The predicted velocity field and eddy viscosity are then used for solving the solute transport equation to predict solute transport rates. The hydrodynamic and solute transport models have been applied to the experimental studies undertaken by Wood and Liang (1989) and the results obtained from both the linear and non-linear k-∊ models are compared with their results. This comparison clearly shows the influence of the secondary currents upon the mixing processes.

Modelling sediment fluxes in estuarine waters using a curvilinear coordinate grid system

A boundary-fitted finite-difference numerical model, capable of predicting two-dimensional depth-integrated tidal flows, has been refined and extended to include sediment transport processes. The sediment fluxes have been considered as the sum of both suspended and bed load fluxes. The highly accurate ULTIMATE QUICKEST scheme has been used to represent the advective terms in solving the advective-diffusion equation for suspended sediment transport. Considerable effort has also been directed towards the development of an appropriate source-sink term to represent the erosion and deposition of the bed material which does not depend upon the vertical distribution profile calibrated at the site. The model has been applied to simulate tidal flows and sediment fluxes in the Humber Estuary in the U.K. The predicted velocities and water elevations have compared favourably with measured data, thereby leading to the potential for accurately predicting sediment concentration distributions. Comparisons between the numerical model predictions of sediment fluxes and field data were also made at three sites along the estuary where field data existed. Overall the quality of these comparisons was encouraging, particularly since no tuning was necessary.

Three-dimensional modelling of water quality in the Humber Estuary

Abstract Details are given herein of the development and application of a refined three-dimensional layer integrated model to predict water elevations, layer averaged velocity components, distributions of conservative and non-conservative water-quality constituents and sediment transport fluxes in estuarine and coastal waters. The model involves using the finite difference technique to solve the equations of mass and momentum conservation and the transport equations for a range of water quality indicators and sediment transport forms. The momentum equations include the effects of the Earths rotation, refined bed and surface shear stresses and a zero or two-equation turbulence model. The model outlined has been applied to a number of site-specific estuaries for modelling flow, water-quality and sediment transport processes, with details reported herein of the model application to the Humber Estuary, in the U.K.