ABSTRACT

Shallow water studies of ship hydrodynamics typically examine a single, constant underwater canal cross-section at a time. In practice, the underwater cross-sectional area and shape of the waterway is rarely maintained constant over long distances. This study presents an attempt to quantify the effects of an abruptly varying water depth by numerically modelling such a condition using CFD. The results show that waves propagate and refract in the numerical towing tank in a physically consistent manner showing less than 0.1% error in the dissipation of a solitary wave when compared to analytical relations. A strong boundary layer is formed on the canal bottom almost as soon as the ship enters the shallower region. The resistance increase, resulting from the depth change is up to approximately 226% of the initial value near critical speeds.

摘要

船舶流体动力学的浅水研究通常一次检查一个单一的、恒定的水下运河横截面。在实践中，水道的水下横截面积和形状很少在长距离内保持恒定。本研究试图通过使用 CFD 对这种条件进行数值模拟来量化突然变化的水深的影响。结果表明，与解析关系相比，波以物理一致的方式在数值拖船舱中传播和折射，在孤立波的耗散中显示小于 0.1% 的误差。几乎在船舶进入较浅区域时，运河底部就会形成坚固的边界层。由深度变化引起的阻力增加高达临界速度附近初始值的大约 226%。