大跨度三心柱面网壳风压分布试验研究

通过大气边界层风洞刚性模型同步测压试验,对大跨度三心柱面网壳表面风压分布特性进行了研究。根据试验结果分析了结构不同风向下的平均和脉动风压分布、典型测点脉动风压谱以及相关性等。结果表明:风向角对网壳表面风压分布有较大的影响,一般情况下,结构迎风面为正压区,顶部为负压区,尾流区受分离、涡脱和再附等特征紊流影响明显;结构的边沿处受柱涡、锥形涡影响明显,风压梯度变化剧烈。迎风面大部分区域脉动风压功率谱类似于典型的纵向风湍流谱,呈单峰形状,主要激励为来流湍流;边沿处风压谱受特征湍流影响明显。结构表面相关性随测点间距离的增加而不断减小;风向不同,相关性衰减差别较大。

Brain control interface (BCI); electroencephalogram (EEG); steady-state visual evoked potentials (SSVEP); electrooculography artifact; adaptive neuro-fuzzy inference system (ANFIS)

The wind pressure characteristics of the surface of a large-span three-centered cylindrical reticulated shell are investigated using a rigid model in a atmospheric boundary layer wind tunnel and synchronized pressure measuring tests. The mean and fluctuating wind pressure distribution characteristics with typical wind directions, the power spectrum and the coherence of the fluctuating wind pressure between different measuring points are experimentally analyzed. The results show that the wind direction has a significant impact on the wind pressure distribution on the reticulated shell surface. In general, the windward of the reticulated shell is the positive pressure area; a negative pressure zone is formed on the top of shell under the impact of characteristic turbulence, such as the separation and reattachment of the air flow, and also the vortex shedding; at the edge of the shell, the wind pressure is obviously influenced by the column and conical vortexes, and violently changes. Furthermore, single peaks are also observed in the fluctuating wind power spectrum in most areas of the windward. It is similar to the typical longitudinal wind turbulence spectrum and can be deduced that the incoming wind turbulence is the major contribution to the along-wind pressure. In addition, the attenuation difference of the coherence is changed with the wind directions, and the coherence of the measuring points along the wind direction is stronger than those along the cross-wind direction.