Numerical Modelling of Wash Waves Generated by Ships Moving over An Uneven Bottom  

作　　者：LI Ming-xin YUAN Zhi-ming BAI Xu LI Yong-zheng CHENG Yong TAO Long-bin 

机构地区：[1]School of Naval Architecture and Ocean Engineering,Jiangsu University of Science and Technology,Zhenjiang 212100,China [2]Department of Naval Architecture,Ocean and Marine Engineering,University of Strathclyde,Glasgow G11XQ,UK

出　　处：《China Ocean Engineering》2023年第1期145-153,共9页中国海洋工程（英文版）

基　　金：financially supported by Natural Scienceof University of Jiangsu Province (Grant No.22KJB580004);the Key R&D Projects in Guangdong Province (Grant No.2020B1111500001);the Jiangsu Province“Six Talents Peak”High-Level Talents Support Project (Grant No.2018-KTHY-033)。

摘　　要：Unsteady wash waves generated by a ship with constant speed moving across an uneven bottom topography are investigated by numerical simulations based on a Mixed Euler–Lagrange(MEL) method. The transition is accomplished by the ship traveling from the depth h1 into the depth h2 via a step bottom. A small tsunami would be created after this transition. However, the unsteady wave-making resistance induced by this new phenomenon has not been well documented by literature. Therefore, the main purpose of the present study is to quantify the effects of an uneven bottom on the unsteady wash waves and wave-making resistance acting on the ship. An upwind differential scheme is commonly used in the Euler method to deal with the convection terms under free-surface condition to prevent waves in the upstream. Evidently, it cannot be applied to the present problem due to upstream waves generated by the ship would be dampened by the upwind scheme. The central differential scheme provides more accurate results,but it is not unconditionally stable. An MEL method is therefore employed to investigate the upstream wave generated by the ship moving over the uneven bottom. Simulation results show that the hydrodynamic interaction between the ship and the uneven bottom could initiate an upstream tsunami, as well as unsteady wave-making resistance on ships.The unsteady wave-making resistance oscillates periodically, and the amplitude and period of the oscillations are highly dependent on speed and water depth.

关 键 词：uneven bottom upstream wave unsteady wave resistance numerical simulation periodic oscillation 

分 类 号：P75[天文地球—海洋科学]