横浪中液舱晃荡与养殖工船耦合运动

Coupled Motion of Tank Sloshing and Aquaculture Platform in Regular Beam Sea

多液舱养殖工船需长时间系泊在深远海区域,载液率极高,所处海况复杂,对其开展耐波性研究尤为重要。基于黏性流理论,以Stokes 5阶波模拟实际规则波,借助VOF方法捕捉自由液面,采用重叠网格技术实现船体的自由运动,通过数值计算研究实尺度下液舱对不同频率横浪中工船运动响应的影响。计算结果表明,液舱晃荡对船体运动的影响随海况变化,当船体横摇运动2阶频率与液舱固有频率相近时会产生共振,液舱晃荡周期随之改变,从而使船体的横摇运动幅度增大近30%。此外,当船体两侧都布置液舱时,横浪中迎浪侧的液舱晃荡较背浪侧更为剧烈,其垂向受力幅值变化范围约为后者的3倍。

The multi-tank aquaculture platform needs to be moored in deep-sea area for a long time.Its high liquid ratio and the complicated sea conditions make it particularly important to do sea-keeping performance research.Based on the theory of viscous flow,the fifth-order stoke wave is used to simulate the actual regular waves.The free surface is captured by the VOF method,and free motion of the platform is achieved by overlapping grids.The influence of real-scale tank sloshing on the motion of multi-tank aquaculture platform in beam sea is studied by numerical simulation.The calculating result shows that following the change of sea states,the influence of tank sloshing on the hull changes.When the secondary frequency of the hull rolling motion is close to the natural frequency of the tank,it goes to resonate and the sloshing period of the tank changes simultaneously,which consequently increases the roll motion amplitude of multi-tank aquaculture platform by nearly 30%.In addition,while there are tanks on both sides of the hull,the sloshing of the tank on the heading side is more severe in beam sea,the variation range of its vertical force amplitude is about three times that of the other.