In this work, a model called ESTA III has been developed and described in detail, which consists of two sub-models: a horizontal 2-d model for tides and "short waves" (in engineering sense) and a 3-d model. The 2-d model for "short waves" is third-order accurate and provides good results in simulating the solitary wave propagation. The third-order accuracy is achieved by the correction of the truncated terms. The numerical features and effects on the solution of the truncated terms in the momentum equations are investigated through the solitary wave simulations....[ Read more ]

In this work, a model called ESTA III has been developed and described in detail, which consists of two sub-models: a horizontal 2-d model for tides and "short waves" (in engineering sense) and a 3-d model. The 2-d model for "short waves" is third-order accurate and provides good results in simulating the solitary wave propagation. The third-order accuracy is achieved by the correction of the truncated terms. The numerical features and effects on the solution of the truncated terms in the momentum equations are investigated through the solitary wave simulations.

For the "short-wave" computations nonreflecting boundary conditions have to be included in the model. In this work, we also improved the nonreflecting boundary conditions proposed by Hedstrom. The distortion to the prescribed incoming wave profiles of original Hedstrom's formulations are studied theoretically. A new set of the nonreflecting boundary conditions is then proposed for the "short-wave" computations, which also retains all the important features of the original form, such as the inclusion of forcing terms at the open boundary.

For the 2-d tidal computations, the drying-flooding procedures are suggested to simulate the moving sea-land boundary on the inter-tidal flats, which works well in the computations of the tides in Pearl River estuary.

The algorithm of the 3-d model is actually an extension of the 2-d model, which can, by setting a switch, revert to the horizontal 2-d model or even l-d model having the implicit solutions. The 3-d model can also be either third-order or second-order accurate in the horizontal plane. This model has good numerical stability according to our applications to the Pearl River estuary.

[bolt ESTA][three vertical bars] has been applied to simulate the tides in Pearl River estuary. The computations provide encouraging results for the 2-d and 3-d flow in the bay when compared to field measurements. The results provide us with details about the tidal currents in the bay and will be useful for future studies on the water environment of the bay.