固定式平台上部组块风载荷研究

Study on Wind Load on the Topside Modules of Fixed Platforms

固定式平台上部组块结构复杂,难以通过统一的公式精确计算平台的风载荷,也难以考量平台模块间的遮蔽和干扰效应。为此,以南海某固定式平台为例,借助国内先进风洞实验室,对平台上部组块进行风洞试验,测定其在全风攻角下的风压分布、各模块的体型系数以及风载荷;并基于CFD技术对其进行数值仿真,将风洞试验结果、数值仿真结果和规范公式计算结果进行对比分析。分析结果表明:风攻角对风压系数、体型系数以及风载荷影响较大,不同风攻角下平台各个模块风压系数和体型系数不同,其值在0.1~2.2范围内变化;数值仿真与风洞试验在计算平台平均风压分布、结构体型系数以及风载荷时比较接近,随风攻角的变化趋势亦基本相同,且仿真结果较风洞结果对风攻角的变化影响反映更加细致。考虑到风洞试验的高昂成本以及模型缩尺的影响,对大型导管架上部组块结构风载荷精细评估时,建议采用数值仿真代替风洞试验。所得结论可为我国导管架平台结构设计和结构安全评估提供参考。

The complex structure of the topside modules of the fixed platform makes it difficult to accurately calculate the wind load of the platform through a unified formula,and to consider the shadowing and interference effects between the platform modules.To address the problem,taking a fixed platform in the South Sea of China for case study,with the help of a domestic advanced wind tunnel laboratory,a wind tunnel test was conducted on the topside modules of the platform to measure the wind pressure distribution,the shape factor of each module and the wind at the full wind attack angle,which were numerically simulated based on CFD technology.Comparative analyses of wind tunnel test results,numerical simulation results and standard formula calculation results were conducted.The analyses results show that the wind attack angle has a great influence on the wind pressure coefficient,body shape coefficient and wind load.The wind pressure coefficient and body shape coefficient of each module of the platform under different wind attack angle are different,varying within the range of 0.1~2.2.The numerical simulation and wind tunnel test are in good agreement in calculation of the platform average wind pressure distribution,structure size coefficient and wind load,and the trend of change with wind attack angle is basically the same.The simulation results reflect the influence of wind tunnel angle change more meticulously than the wind tunnel results.Considering the high cost of the wind tunnel test and the influence of the test model scale,it is recommended to use a numerical wind tunnel instead of the model test for the precise assessment of the wind load on the topside modules of the large jacket platform.