Physical and numerical modelling of sediment transport in the surf zone

目前的研究主题旨在减少有关机制的不确定性，通过该机制，非粘性沉积物（砂粒）被移位，运输和沉积的形式，在碎波带的推移质，由于强烈的湍流产生的波浪破碎。这是建立一个实用的工程工具--数值海滩形态动力学模型--能够预测海岸线的时间和空间演变的重要一步。 沉积物强烈搅动的主要区域称为碎波带。这一物理域位于第一波浪破碎线和海岸线之间，其特征是强烈的波浪搅动和与之相关的水流（离岸流、纵向流、回流等），这些水流代表了沉积物位移的驱动机制。泥沙输运分析将侧重于靠近海岬的区域（波浪底边界层）。 目前的工作将包括实验室工作以及数学和数值建模。本研究将探讨三个主要议题：1。不规则波条件下波浪紊动对近底区域泥沙的卷吸和推移的定性和定量分析。这项任务将包括测量沉积物颗粒的速度和浓度。2.建立了一个新的数值模型，该模型将真实地反映泥沙运动的开始和发展的物理过程。参考水平的新定义（在边界层内）将与影响运动中的沉积物颗粒的惯性效应一起纳入。 该研究项目将使研究生的培训和形成成为高技能的水力工程师和未来的研究人员和/或设计师。

The present research theme aims to reducing uncertainties concerning the mechanisms through which non-cohesive sediments (sand particles) are being displaced, transported and deposited in the form of bedload in the surf zone, due to intense turbulence generated by wave breaking. This is an essential step in constructing a practical engineering tool - in the form of Numerical Beach Morphodynamic Model - capable of predicting the time and space evolution of the coastline.    The major zone of intense sediment agitation is known as the surf zone. This physical domain is located between the first wave breaking line and the shoreline and is characterized by intense wave agitation and currents associated with it (rip currents, longitudinal currents, undertow, etc) which represent the driving mechanism for sediment displacement. The analysis of sediment transport will focus on the area close to the seabead (Wwave Bottom Boundary Layer, WBBL).  The current work will include both laboratory work and mathematical and numerical modeling. Three main topics will be investigated under the current research: 1. The qualitative and quantitative analysis of the sediment entrainment and displacement in the area close to the seabed due to wave-induced turbulence under irregular wave conditions. This task will include sediment particles velocity and concentration measurements. 2. Formulation of a new numerical model for the WBBL which would realistically reflect the physics of the inception and devleopment of the sediment movement. A new definition for the reference level (inside the BBL layer) will be incorporated together with the inclusion of the inertial effects affecting the sediment particle in motion.    The research project will enable the training and formation of graduate students towards becoming highly skilled hydraulic engineers and future researchers and/or designers.