杜晓庆，成文涛，董浩天，马文勇

摘   要：為阐明双方柱中上游方柱尾流对下游方柱脉动气动性能的影响，在雷诺数Re = 8.0 × 104均匀来流条件下，完成了间距比P/B = 1.25～5（其中P为柱心距，B为方柱边长）、全风向角α = 0° ～ 90°的双方柱测压风洞试验. 分析了不同P/B条件时下游方柱脉动气动力、升力功率谱、Strouhal数和气动力展向相关性随α的变化规律. 发现P/B < 3时下游方柱的脉动气动力整体上小于单方柱，且α ≥ 40°时几乎不随风向角变化. 但在3 ≤ P/B ≤ 5且0° ≤ α ≤ 30°时下游方柱脉动阻力远大于单方柱. 下游方柱的脉动气动力、升力功率谱和气动力展向相关性随α的变化规律在P/B = 3前后差异显著. P/B < 3时，下游方柱旋涡脱落受到显著抑制;P/B > 3时，下游方柱的脉动气动性能近似于单方柱.

关键词：双方柱;脉动气动性能;间距比;风向角;风洞试验

中图分类号：TU 311                             文献标志码：A

Experimental Study on Fluctuating Aerodynamic Characteristics

of Two Square Cylinders at Various Incidence Angles

DU Xiaoqing1，2，CHENG Wentao1，DONG Haotian3？覮，MA Wenyong4

（1. Department of Civil Engineering，Shanghai University，Shanghai 200444，China;

2. Wind Engineering and Aerodynamic Flow Control Research Center，Shanghai University，Shanghai 200444，China;

3. School of Mechanics and Engineering Science，Shanghai University，Shanghai 200444，China;

4. Wind Engineering Research Center，Shijiazhuang Tiedao University，Shijiazhuang 050043，China）

Abstract：To reveal the influence of the wake released from the upstream square cylinder on fluctuating aerodynamic characteristics of the downstream one，wind tunnel tests were carried out to measure the pressure on twin square cylinders，under a uniform inflow condition with a Reynolds number Re of 8.0×104，space ratios P/B of 1.25～5 （where P is the central distance，B is the side length） and various incidence angles of 0° ≤ α ≤ 90°. The variations of fluctuating aerodynamic forces，power spectrums of lift，Strouhal numbers and spanwise aerodynamic correlations with α are investigated considering the multiple space ratios. When P/B < 3，fluctuating forces on the downstream cylinder are roughly smaller than those on a single square cylinder，and they change little at α ≥ 40°. However，when 3 ≤ P/B ≤ 5 and 0° ≤ α ≤ 30°，the fluctuating drag on the downstream cylinder is significantly stronger than that on a single one. The fluctuating forces，power spectrums of lift and spanwise aerodynamic correlations on the downstream cylinder change dramatically when P/B reaches 3. When P/B < 3，vortex shedding from the downstream cylinder is significantly suppressed. When P/B > 3，however，the fluctuating aerodynamic properties of the downstream cylinder become similar to those of a single one.

Key words：two square cylinders;fluctuating aerodynamic characteristics;space ratio;various incidence angle;wind tunnel experiment

超高层建筑在大城市中常以群体建筑的形式存在，其周围流场存在复杂的气动干扰. 在气动干扰影响下其风荷载和风致响应特征与单体建筑相比有着显著的区别[1-5]. 受上游建筑尾流旋涡的激励作用，下游建筑易发生风致振动，对其抗风性能造成不利影响[6]. 常以均匀来流中的双方柱作为群体超高层建筑的简化模型. 双方柱绕流受众多因素影响，流场结构复杂，研究双方柱，特别是下游方柱的脉动气动性能有助于理解超高层建筑的气动干扰机理.

国内外学者对二维单方柱的气动力与流场结构已有了非常深入的研究[7-9]，其氣动力与流场结构受风向角的影响显著，而受雷诺数的影响较小. 对双方柱的研究则主要针对串列[10-13]及并列[14-17]两种布置形式，方柱间距比P/B（其中P为柱心距，B为方柱边长）对串列和并列方柱的表面风压、气动力和斯托罗哈数等气动参数影响显著. 对于串列双方柱，Sakamoto等[10]通过风洞试验……