| 引用本文: | 彭思,王汉封,李石清.顶部定常吸气对高层建筑模型气动力的影响[J].哈尔滨工业大学学报,2017,49(12):159.DOI:10.11918/j.issn.0367-6234.201703123 |
| PENG Si,WANG Hanfeng,LI Shiqing.The free-end steady suction effects on the aerodynamic forces of high-rise building model[J].Journal of Harbin Institute of Technology,2017,49(12):159.DOI:10.11918/j.issn.0367-6234.201703123 |
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| 摘要: |
| 为减少高层建筑受到的风荷载，提高高层建筑抗风性能，提出一种顶部吸气的主动控制方法。在一高宽比为H/d=5的正方形截面柱体的高层建筑模型上，通过在其顶部前边缘开设狭缝进行吸气来实现流动控制。通过风洞试验研究了顶部吸气对气动力与顶部分离流的影响.利用流动可视化与流场测试结果揭示了顶部狭缝吸气的控制机理.实验对比了不同吸气系数Q (=U/U∞, U为狭缝吸气速度)对气动力控制效果的影响, 并对Q=0, 1和3的三种工况下风压分布与顶部剪切流进行了详细对比.研究发现狭缝吸气改变了顶部分离流特性, 并对模型所有高度上的气动力均有显著影响. Q=1时控制效果最佳, 脉动阻力与脉动升力分别减小17.8%和45.5%.此时顶面分离流被削弱并伴随有再附现象且湍流强度较大, 最有利于顶部剪切流与尾流间的动量交换, 从而削弱柱体展向涡脱落与脉动气动力.
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| 关键词: 空气动力学 有限长方柱体 定常吸气 流动分离 流动控制 |
| DOI：10.11918/j.issn.0367-6234.201703123 |
| 分类号:O355 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(11472312) |
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| The free-end steady suction effects on the aerodynamic forces of high-rise building model |
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PENG Si1,WANG Hanfeng1,2,LI Shiqing1
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(1.School of Civil Engineering, Central South University, Changsha 410075, China; 2.National Engineering Laboratory for High-speed Railway Construction (Central South University), Changsha 410075, China)
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| Abstract: |
| To reduce wind loads on high-rise buildings, a new active aerodynamic control method named steady suction on the top of the building was introduced. The effects of free-end leading edge steady suction on the aerodynamic forces and free-end separation of a finite-length square cylinder were experimentally investigated in a wind tunnel. Flow visualization and flow field measurement were utilized to reveal the control mechanism. The dependence of aerodynamic forces on the suction ratio Q(=U/U∞) was studied. The pressure distribution and the shear flow above the free end were compared in detail for Q=0, 1 and 3. The results show that the slot suction changes the flow separation on the free end significantly and also the aerodynamic forces on the whole cylinder span. The best control result appears at Q=1, with the fluctuation drag and lift reduced by 17.8% and 45.5%, respectively. At this suction ratio, the flow separation at the leading edge is weakened with reattachment and strong turbulence fluctuation presence on the free end, which results in strong momentum transport between the free-end shear flow and the wake and suppresses the vortex shedding and aerodynamic forces efficiently.
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| Key words: aerodynamic forces finite-length square cylinder steady suction flow separation flow control |
