基于RANS/LES混合方法的近岸水域波浪增阻影响的数值模拟

Numerical Simulation of Influence of Rough Drag in Coastal Waters Based on RANS/LES Hybrid Method

分析船舶在近岸水域航行时所受波浪增阻大小的影响因素,以寻求降低波浪增阻的方法。基于近岸水域中船舶阻力理论,采用雷诺平均(RANS)和大涡模拟(LES)相结合的方法进行数值求解,并运用两相流方法和造波消波技术建立数值水池模型。用Fluent求解器对船舶在不同工况下的波浪增阻进行数值模拟。试验结果表明:用该方法对近岸水域航行的船舶进行波浪增阻的数值模拟可有效提高计算机运算效率,在粗糙网格层面上得到的计算结果精度良好;船舶在近岸水域中航行时的波浪增阻随波高的增加而增加,并且与船体湿润面积呈正相关;船舶在近岸水域以中低速航行时所受波浪增阻随弗劳德数的增加而增加。该研究为近岸水域通航船舶减小航行阻力提供了可行的方法与思路。

The influence factors of rough-sea resistance on ships sailing in coastal waters are analyzed to find ways to reduce rough-sea resistance. Based on the ship resistance theory in near shore waters, the numerical solution is carried out by combining Reynolds average Navier Stokes(RANS) and large eddy simulation(LES),and a numerical pool model is established by two-phase flow method and wave generation and elimination technology. The Fluent solver is used to simulate the rough-sea resistance of ships under different working conditions. The experimental results show that: the numerical simulation of rough-sea resistance of ships sailing in near shore waters can effectively improve the computational efficiency, and the computational result son rough grid level are of good accuracy;the rough-sea resistance of a ship in near shore waters increases with the increase of wave height and is positively correlated with the wet area of ship hull;with the increase of Froude number, the resistance to ships sailing at low and medium speed in near shore waters increases. A feasible method and thought are provided for reducing the resistance of ships sailing in near shore water.