沉管隧道浮运水动力学性能的数值分析

为了正确评估沉管隧道管段在水中浮运的水动力学特性，确定合理的水上施工参数，以广州生物岛沉管隧道为研究对象，在缩尺模型试验的基础上，采用CFD软件STAR-CCM＋的改进型SST k-ω模型，对不同施工参数条件下的管段周围的流场进行了数值模拟，分析了管段所受水动力作用的特性．结果表明，干舷值的变化对阻力系数的影响最大可达35．9％；受水横流的作用，在拖速为0．6-1．2m／s时，管段拖运方向的阻力系数随着拖速的增加而减小；波浪对阻力系数也有影响，拖速越大，影响越明显，当拖速从0．8m／s增加到1．2m／s时，管段拖运方向的阻力系数与无波工况相比，增幅可达36．75％．

Numerical Simulation of the Hydrodynamic Characteristics of the Immersed Tube Tunnel in Tugging

In order to evaluate the hydrodynamic characteristics of the immersed tube tunnel in tugging and chose the suitable parameters, this article bases on modeling test and takes Biologic Island ITT to test the computational modeling by SST k-ω of STAR-CCM ＋ . The research simulates different pa- rameters of the pipe under the condition of the surrounding flow field, and analyzes the hydrodynamic characteristics of tube sections. The results show that the maximum variation range of the drag coefficients reached 35.9% due to the change of the freeboard. Being affected by the water cross-flow, the coefficients gradually decreased with the increase of the moving speeds of the tube tunnel in the range of the speeds from 0.6 to 1.2 m/s. Waves also have an impact on the coefficients, and the greater the moving speed of the tube tunnel is, the more obvious the impact is. Compared with the condition without wave, the maximum amplitude of the coefficient can be 36.75% under the influence of wave if the moving speed of the tube tunnel grows from 0.8 to 1.2 m/s.