圆角化3∶1二维矩形柱体风压分布的雷诺数效应

Reynolds Number Effects on Wind Pressure Distributions of 3∶1 Rectangular Prisms with Various Rounded Corners

摘要:

在低紊流度的均匀场中，研究了4种圆角率（0, 5%, 10%和15%）的3∶1二维矩形柱体模型的风压分布随雷诺数的变化规律.从模型周围气流绕流的角度解释了圆角处理的矩形柱体模型的雷诺数效应的机理，并分析了雷诺数对各模型的背风面中点的风压系数的影响.试验雷诺数的变化范围为1.1×105~6.8×105.结果表明，四种圆角率模型的风压分布都受雷诺数的影响，但圆角率为0和5%的模型受雷诺数影响较小，圆角率为10%和15%的模型受雷诺数影响明显.圆角处理措施对矩形柱体模型雷诺数效应的影响主要是通过影响分离剪切层在模型侧面前缘的形成及其在侧面后部区域的再附，进而影响模型的气动特性，使模型更易受雷诺数的影响.

关键词:圆角; 矩形柱体; 平均风压分布; 脉动风压分布; 雷诺数效应

Abstract:

Experiments were conducted of measuring wind pressures on the surface of 3∶1 rectangular prisms with rounded corner ratio of 0, 5%, 10% and 15% in low turbulence uniform flow for the testing Reynolds number ranging from 1.1×105 to 6.8×105. The Reynolds number effects on wind pressure distributions were studied, and the mechanisms of Reynolds number effects were revealed by analyzing the variations of the flow around the model. The results show that wind pressure distributions of four models are all affected by the Reynolds number. Compared with the models with 0 and 5%, the wind pressure distributions of models with 10% and 15% are more sensitive to the Reynolds number. The corner rounding modification influences the Reynolds number effects of 3∶1 rectangular prisms by affecting the formation of the separated shear layer, which also affects the flow reattachment of the boundary layer as well as the aerodynamics of the body.

Key words:rounded corner; rectangular prism; mean pressure distribution; fluctuating pressure distribution; Reynolds number effects