大型户外独立柱广告牌风压分布特性

Characteristics of Wind Pressure Distribution on Large Single Column Supported Billboards

通过风洞试验,测量三面板和双面板两种独立柱广告牌模型的面板表面风压,研究其分布规律.讨论面板表面平均和脉动风压系数在不同风向角下的分布特性及随风向角的变化,以及面板表面典型测点脉动风压的频域特性.结果表明:各块面板表面的平均风压系数绝对值均随风向角的增加而逐渐减小;对于背风面板,面板边缘附近的平均风压系数绝对值及脉动风压系数要比面板内部区域大;在各个风向角下,单个面板两表面均存在风压的叠加或抵消效应;迎风面板外表面的脉动风压主频低于背风面板外表面脉动风压的主频,能量也较小,各块面板的内表面脉动风压频带均较宽,能量更小;广告牌立柱对于面板表面局部风压系数的影响较大.

The wind pressure distribution characteristics on two-panel and three-panel billboards supported by single column were studied with wind tunnel model tests.The distribution characteristics of mean and fluctuating wind pressure coefficients in different wind directions, the influences of different wind directions on mean and fluctuating wind pressure coefficients and the frequency-domain characteristics of the fluctuating wind pressure of typical pressure taps on the surfaces of the panels were discussed.The results show that the absolute values of mean wind pressure coefficients on each panel decrease with the increase of wind direction;the absolute values of mean wind pressure coefficients and fluctuating wind pressure coefficients near the edge of leeward panels are larger than those on the interior areas of leeward panels;either the superimposition or offset of the wind pressure exists on both surfaces of a single panel in various approaching directions; the main frequency of fluctuating wind pressure spectra of the outside surface of windward panel is lower than that of internal surface of leeward panel,and so is the energy.In comparison,the bandwidth of fluctuating wind pressure spectra of internal surfaces of panels are wider and the energies are lower;the local wind pressure coefficients on the surfaces of panels are greatly influenced by the columns of billboards.