Concepts of a submerged floating tunnel (SFT) for novel sea-crossings have been researched in recent years. An SFT tube should be moored afloat by tensioned mooring systems to maintain the tube position under complex hydrodynamic loads. In-line force is amongst the dominant hydrodynamic parameters in the SFT cross-section design and the mooring system reliability evaluation. Selecting a suitable in-line force computation method is crucial to successful and accurate SFT cross-section optimization. The transition SST model is an effective turbulence transition prediction tool in the boundary layer computation subjected to tidal flow at both low and high Reynolds numbers. Two types of parametric Bézier curves applied in airfoil optimization are used to describe the SFT cross-section. We show that an SFT cross-section described by a leading-edge Bézier-PARSEC (BP) curve has better hydrodynamic performance than a trailing-edge BP curve of equal aspect ratio (AR). To avoid large flow separation, an AR not exceeding 0.47 is recommended. An SFT cross-section design should balance hydrodynamic performance and construction cost. The SFT cross-section with AR = 0.47 using the leading-edge BP curve with fixed clearance has a comparatively small in-line force and a minimum material cost.

近年来，人们研究了用于新型跨海的水下浮式隧道 (SFT) 的概念。SFT 管应通过张紧系泊系统漂浮在海上，以在复杂的流体动力载荷下保持管的位置。在线力是 SFT 横截面设计和系泊系统可靠性评估中的主要水动力参数之一。选择合适的在线力计算方法对于成功和准确的 SFT 横截面优化至关重要。过渡 SST 模型是一种有效的湍流过渡预测工具，适用于在低雷诺数和高雷诺数下受潮汐流影响的边界层计算。在翼型优化中应用的两种参数贝塞尔曲线用于描述 SFT 横截面。我们表明，由前沿 Bézier-PARSEC (BP) 曲线描述的 SFT 横截面比等纵横比 (AR) 的后沿 BP 曲线具有更好的流体动力学性能。为避免大流量分离，建议使用不超过 0.47 的 AR。SFT 横截面设计应平衡流体动力性能和施工成本。使用具有固定间隙的前沿 BP 曲线的 AR = 0.47 的 SFT 横截面具有相对较小的在线力和最低的材料成本。