孤立波浪边界干扰下流线型箱梁气动特性

近海流线型箱梁主梁距水面较低时，气动特性极易受到极端波浪边界的干扰.为研究极端波浪边界干扰下流线型箱梁气动特性，以孤立波浪模拟极端波浪，基于FLUENT软件，采用铺层网格技术建立了模拟运动孤立波浪边界干扰下流线型箱梁气动特性的数值模型；利用所建立并验证的数值模型研究了不同参数下运动孤立波浪边界对流线型箱梁气动特性（静气动力系数、涡量场以及平均压力系数和脉动压力系数分布）的干扰.分析结果表明：不同孤立波浪边界运动速度干扰下流线型箱梁气动特性明显区别于无波浪工况；随波浪边界运动，迎风角处剪切层方向相比于梁底转折角处（8°风攻角）及梁顶转折角处（-8°风攻角）剪切层方向变化明显；在运动孤立波浪边界干扰下，箱梁抖振响应会随风攻角幅值增大呈增大趋势.

Aerodynamic Performance of Streamlined Box Girder Under Interferences from Solitary Wave Boundary

When an offshore streamlined box girder is close to the water surface, the aerodynamic performance is easily interfered by extreme wave boundary conditions. To investigate the aerodynamic performance of the streamlined box girder under interferences from extreme wave boundary, the extreme wave is simulated using solitary wave. Based on FLUENT software, a numerical model for the aerodynamic performance of the streamlined box girder under interferences from moving solitary wave boundary is established by layering mesh method. The model is validated and then used to study the interferences from the moving solitary wave boundary on the aerodynamic performance, including aerostatic force coefficients, vorticity magnitude field, and distributions of the mean and fluctuating pressure coefficients of the streamlined box girder, under different parameters of wave boundary moving speed, wind attack angle and bridge clearance. The analysis results show that the aerodynamic performance of the streamlined box girder under the interferences from different solitary wave boundary moving speeds is apparently different from that of no-wave case. With wave boundary moving forward, the direction of the shear layer at the windward corner changes significantly compared to that at the corner of bottom surface (8° wind attack angle) and the top corner of upper leeward surface (?8° wind attack angle). Under the interferences from the moving solitary wave boundary, the buffeting response of the girder will be strengthened with the increment of the magnitudes of wind attack angles.