A hybrid Boussinesq-SPH wave propagation model with applications to forced waves in rectangular tanks.

摘要

Accurate modeling of water waves generated by forcing partially filled containers is important for a variety of engineering problems ranging from design of containers to transport liquids to estimations of run up and overtopping of earthquake induced water waves in lakes. The goal of this dissertation is the development of a robust and efficient numerical model that can be applied to model forced free surface waves in large domains.;The first part of this research project focuses on the modifications and improvements made to a fully nonlinear Boussinesq model, FUNWAVE (Kirby et al. (1998)), in order to apply it to model this phenomenon. New boundary conditions are implemented to handle external forcing. Existing implementations of reflective boundary conditions have been modified to enhance their accuracy. The final model is compared to experimental sloshing data and good free surface comparisons are obtained.;The second phase of the dissertation deals with the development of a Lagrangian numerical model of the Navier-Stokes equations called SPHysics. The model is based on the numerical method called Smoothed Particle Hydrodynamics. The details of the numerical model and various enhancements made to the interpolation schemes are discussed. New boundary conditions for Smoothed Particle Hydrodynamics are presented. The model results are found to compare well with experimental data.;One of the advantages of Boussinesq models is that they are both accurate and computationally efficient in modeling wave propagation. These models are 2D approximations of the 3D flow and hence are much faster than fully 3D models. However, using these models it is difficult to study the details of 3D flow features such as those observed during the wave breaking process.;The SPH models of the Navier-Stokes equations, with appropriate closure sub-models, are known to be able to simulate breaking induced turbulent flows. The Lagrangian nature of the technique also makes it easy to track the multiply connected free surfaces observed during breaking and subsequent splash up processes. No special treatments are needed to measure runup and over-topping using these models.;The final part of this dissertation deals with the development of a hybrid Boussinesq-SPH model. The hybrid model is developed to utilize the aforementioned advantages of both techniques. The Boussinesq model is used to propagate waves over the non breaking region of the computational domain. The SPH model is used to handle the transformation in the breaking zone and runup. The coupling algorithm is shown to work well when applied to the propagation of a solitary wave over a constant depth tank.