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基于Fluent软件平台,进行了平滑流场内不同雷诺数情况下半圆球形屋盖结构非定常绕流大涡模拟计算。数值模拟中,以来流平均风速和半圆球屋盖直径定义的3个雷诺数Re为6.6×10~4、3.0×10~5和2.0×10~6。将数值模拟所得屋盖表面平均和脉动风压与已有文献风洞试验结果进行对比,验证了文中数值模拟结果的有效性,并分析了不同大涡模拟参数对数值模拟结果的影响。比较分析了3个雷诺数下半圆球形屋盖结构周围的平均流场和瞬态涡结构分布规律,研究半圆球屋盖结构风荷载的形成机理。结果表明:在保证第1层网格到壁面的无量纲距离y~+≤5.0情况下,进一步加密网格对屋盖表面风压分布影响不明显,而亚格子模型对屋盖表面风压分布影响显著。随着雷诺数的增加,屋盖表面流动分离点逐渐下移,地面上的流动再附点则逐渐前移,上游回流区和下游分离泡均逐渐变小;屋盖表面流动分离区剪切涡形状随雷诺数的增大逐渐变得不规则。
Based on the Fluent software platform, large eddy simulation of unsteady flow around semicircular spherical roof structures with different Reynolds numbers in a smooth flow field is carried out. In the numerical simulation, the three Reynolds numbers Re defined by the average wind speed and the hemispherical dome diameter are 6.6 × 10 ~ 4, 3.0 × 10 ~ 5 and 2.0 × 10 ~ 6. The comparison of the average and fluctuating wind pressure on the roof of the roof with the wind tunnel test results of the existing literature verifies the validity of the numerical simulation results and analyzes the influence of different large eddy simulation parameters on the numerical simulation results. The distribution of the average flow field and transient vortex structure around the lower semicircular spherical roof structure with three Reynolds numbers is analyzed and compared. The formation mechanism of the wind load on the semi-spherical dome roof structure is studied. The results show that in the case of guaranteeing the dimensionless distance from grid 1 to the wall surface y ~ + ≤5.0, the effect of further gridding on the wind pressure distribution on the roof surface is not obvious. However, Significant impact. With the increase of Reynolds number, the surface flow separation point of the roof surface gradually moves down, and the flow reattachment point on the ground surface gradually moves forward, and the upper and lower backflow bubbles gradually become smaller. The shear vortex The shape gradually becomes irregular with increasing Reynolds number.