沿岸航行肥大型船舶的流场偏移特性研究

Study on the Characteristics of Deviation of Flow Field of Full Ship Moving Along a Bank Wall

以国际标准油船KVLCC2为研究对象,基于RANS方程,对其沿岸航行时在浅水与岸壁效应联合作用下船体周围黏性流场的变化特性进行数值模拟。对网格无关性和湍流模型进行验证,并将水动力和流场计算结果与试验值相对比,以验证数值方法的可行性。改变水深、船-岸距离和航速3个参数,计算对比周围流场的变化、船体表面压力的变化和伴流分数的变化,重点分析船尾伴流的偏移特性,给出桨盘处伴流分数的变化趋势和平均值。研究结果表明,随着水深和船-岸距离的减小,桨盘处伴流分数沿周向的分布呈不对称性;水深和船-岸距离同时减小会使桨盘处流场向岸壁偏移更明显;航速变化对流场偏移的影响较小。

Based on RANS equation,the change characteristics of flow field around the standard oil tanker KVLCC2 moving along a bank wall is numerically simulated under the combined effect of shallow water and bank effect.The grid convergence and turbulence model are verified,and the calculation results of hydrodynamic forces and flow field are compared with the experimental data to verify the feasibility of the numerical method.By changing water depth,ship-bank distance and speed,the flow field around the hull,the pressure change on the hull surface and the wake fraction change are calculated and compared.The deviation characteristics of the wake flow at the stern are analyzed emphatically.The variation trend and average value of the wake fraction at the propeller plane are given.The research result shows that with the decrease of water depth and ship-bank distance,the circumferential distribution of wake fraction at the propeller plane is asymmetric,and when the water depth and the ship-bank distance decrease simultaneously,the deviation of the flow field of the propeller plane to the bank is more obvious,speed has little effect on the flow field deviation.