不同入射浪向下群遮效应的CFD分析

CFD analysis on cloaking effect under waves with different incident directions

基于黏流理论系统地模拟了不同入射浪向的波浪作用下外围浮体数不同时浮体群的群遮现象.首先建立了多浮体水动力计算数值模型;然后模拟了两个典型波浪方向下,外围浮体数为0,4和8时浮体群的复杂干涉现象;最后从结构周围波浪场出发,着重分析了群遮效应对浮体波漂移力的影响机理.结果表明:计算流体动力学(CFD)方法可准确模拟多浮体间的复杂相互干涉;随着外围浮体数增加,群遮效应对中心浮体波漂移力的低减作用更加显著,且群遮效应对浪向的敏感性也逐渐减小;中心浮体波漂移力的降低与其迎浪侧、背浪侧间波面抬高差值的减小密切相关.

Based on the viscous flow theory,the cloaking phenomenon among multi-floating bodies with different number of outer floating bodies was systematically simulated under waves with different incident directions.Firstly,a numerical model for hydrodynamic calculation of multi-floating bodies was developed.Then,the complicated interference phenomenon among floating bodies with total number of the outer floating bodies equal to 0,4 and 8 was numerically simulated under waves with two typical directions.Finally,the influence mechanism of cloaking effect on wave drift force was emphatically studied from the wave field around the structure.Results show that the present computational fluid dynamics(CFD)method has the capability of simulating the complicated interference among multiple floating bodies;as the number of outer floating bodies increases,the reduction of the wave drift force due to cloaking effect is more obvious and the sensitivity of the cloaking effect to the wave directions gradually decreases;the decrease of wave drift force on the inner floating body is closely related to the reduction of wave elevation difference between the weather side and lee side of the body.