大型回流边界层风洞的气动与结构设计

大型边界层风洞是开展风工程研究的必备装备。以浙江大学ZD-1边界层风洞的研制为背景，详细介绍了大型回流边界层风洞气动设计和立式结构设计中的关键问题，在风洞气动设计时采用了收缩比为4∶1的单回路单试验段气动轮廓，在试验段中设置了0．22°的当量扩散角，对拐角导流片外形作了特殊处理，并采用钢结构与混凝土结构相结合的立式结构。流场校验结果表明，大型回流边界层风洞的气动与结构设计能满足设计要求，某些指标甚至达到航空风洞的标准，在试验段中设置扩散角有利于降低轴向静压梯度，立式结构设计对提高试验段气流的水平均匀性有一定的作用，可为今后类似风洞的研制提供参考。

Aerodynamic and structural design of large recirculating boundary-layer wind tunnel

Large boundary-layer wind tunnel is necessary equipment for wind engineering research.In the background of the development of Zhejiang University ZD-1 boundary layer wind tunnel,the key technical problems in the design of the aerodynamic and vertical structure of the large recirculating boundary layer wind tunnel are introduced in detail.Test section of ZD-1 wind tunnel is designed as 4m width and 3m height,the maximum wind speed is designed as 55m/s, and the turbulence intensity is designed as not higher than 0 .5%.With the contraction ratio of 4∶1 ,single test section and single loop aerodynamic profile are used in aerodynamic design,equivalent diffusion angle of 0.22＆#176;is arranged in the test section,and the shape of corner vane is treated specially.The combination of steel structure and concrete structure is used in the vertical wind tunnel structure design.The results of flow field calibration show that the maximum wind speed of wind tunnel reaches 55m/s,the maximum energy ratio reaches 2.0,the hydrodynamic stability coefficient in master test area for wind speed of 40m/s is less than 0.5%,the maximum axial static pressure gradient is 0.0044,and the maximum turbulence intensity is 0.47%.It is showed that all the indexes meet the design requirements,and some indicators reach the standard of aviation wind tunnel.It is worth stressing that setting axial diffusion angle in the test section can reduce axial static pressure gradient,and the dynamic pressure nonuniformity coefficient con-tour shows the characteristics of horizontal distribution in the test section,which confirms that the uniformity of dynamic pressure for horizontal direction is better than vertical direction.Verti-cal structure design plays a certain role for improving the level of horizontal uniformity of the test section,which provides a reference for the design and construction of similar wind tunnels.