聚焦波作用下悬浮隧道水动力特性数值模拟研究

Numerical simulation of hydrodynamic characteristics of submerged floating tunnels under the action of focused waves

【目的】研究聚焦波作用下悬浮隧道水动力及结构动态响应特性。【方法】采用高精度有限体积方法数值求解不可压缩两相流动控制方程,建立高精度数值波浪水槽模型。应用嵌套网格技术,采用四阶Runge-Kutta方法,数值计算了波浪荷载作用下悬浮隧道动态响应的弹簧-质量-阻尼系统。通过设计合理的计算工况,系统分析不同波浪要素及结构动力参数对悬浮隧道水动力特性及结构动态响应的影响。【结果】聚焦波作用下悬浮隧道所受最大水平荷载稍大于竖向荷载,最大水平位移远大于最大竖向位移,约为最大竖向位移的5倍。【结论】随着有效波高的增加,悬浮隧道所受水动力荷载逐渐增大,结构动态响应逐渐增强;水深和谱峰周期对悬浮隧道水动力及结构动态响应的影响有限;随着淹没深度的增加,悬浮隧道所受波浪荷载逐渐减小,结构动态响应逐渐减弱;在相同入射波条件下,悬浮隧道直径越小,动态响应越小。上述研究结果可为悬浮隧道的参数设计提供一定参考。

[Purposes]This work contributes to the existing body of research by systematically carrying out numerical investigations on the hydrodynamic characteristics of submerged floating tunnels under the impact of freak waves generated by wave focusing.[Methods]The high-precision finite volume method is used to simulate the governing equations of incompressible two-phase flow.Additionally,a high-resolution numerical wave tank was established.The spring-mass-damping system,which represents the dynamic response of a submerged floating tunnel under wave loads is numerically calculated using the overset mesh technique and the fourth-order Runge-Kutta method.The hydrodynamic characteristics of submerged floating tunnels are systematically investigated by considering the effects of five prominent factors,i.e.wave height,submersion depth,water depth,wave period,and tunnel diameter.[Findings]When subjected to the impact of focused wave,the maximum horizontal load on the submerged floating tunnel is slightly larger than the vertical load.Furthermore,the maximum horizontal displacement is approximately 5 times that of the vertical displacement.[Conclusions]With the increase of the effective wave height,both the hydrodynamic load on the submerged floating tunnel and the structural dynamic response rises gradually.Results show that the influence of the water depth and wave period on the hydrodynamic and structural dynamic response of submerged floating tunnel is very limited.With the increase of the submersion depth,both the wave load on the submerged floating tunnel and the dynamic response of the structure decrease conversely.Another finding is that under the same incident wave conditions,the smaller the diameter of the submerged floating tunnel is,the less the dynamic responses.Therefore,it is believed that the findings drawn from this paper can further enhance our understanding on the damage mechanism of submerged floating tunnel under freak waves.