拖航工况下半潜平台撑杆波浪砰击敏感性研究

半潜式平台在拖行过程撑杆等细长结构承受的波浪砰击对结构安全影响较大，相关船级社规范中明确要求结构分析过程中需要考虑波浪砰击载荷。基于传统势流理论的数值方法已经被广泛的应用于浮式海洋平台的水动力和砰击载荷的研究，但是对于复杂的粘性干涉效应、波浪爬升、波浪破碎和波浪砰击等实际工程问题不能够运用势流理论准确模拟。非定常的计算流体力学CFD (Computational Fluid Dynamics)方法能够较为准确解决上述问题。因此，本文以982半潜式海洋平台为研究对象，采用计算流体力学中的动态重叠网格方法和流域体积域方法VOF(volume of fluid)，结合水池物理模型试验结果，对平台在拖行工况下撑杆的波浪砰击进行研究。主要对半潜平台撑杆在三种不同流速和风速的拖航工况下撑杆受到的砰击压力的敏感性进行了分析研究，分析波浪砰击下撑杆的瞬态砰击压强分布情况，得到波浪砰击压力危险区域，同时给出拖航工况下撑杆砰击压力系数的变化规律，为分析预报半潜式平台撑杆在复杂的拖航海况下受到的砰击压力提供了参考。

Sensitivity Study of Wave Slamming of Semi-submersible Platform Brace under Towing Condition

The wave slamming of the slender structures such as brace have an important for the structural strength in the towing process of semi-submersible platform. The hydrodynamic and wave slamming load analysis of floating platform have been studied based on the traditional potential flow theory, but the potential flow theory cannot be used to accurately simulate for complex physical phenomena, such as viscous interference effect, wave climbing, wave breaking and wave slamming, and other practical engineering problems. The unsteady Computational Fluid Dynamics method (CFD) can solve the above problems. Therefore, this paper taking 982 Semi-submersible floating platform as an example and combines the tank test results, the dynamic overlapping grid and volume of fluid method in computational fluid mechanics (VOF) are adopted to investigate the wave slamming of brace under towing conditions. The sensitivity of the wave slamming pressure with three different currents and wind speeds under the towing conditions is analyzed. Analyze the transient pressure distribution of the brace under wave slamming, the wave slamming pressure dangerous areas are shown. Meanwhile, the change rules of the slamming pressure coefficient of the brace under the towed conditions is conducted, which provides a reference for analyzing and predicting the slamming pressure of the semi-submersible platform brace in the complex towed conditions.