应用粒子图像速度场仪对泊肃叶流动及圆柱绕流的测量

Application of Particle Image Velocimetry to Measurement of Poisoeullie Flow and Flow around a Circular Cylinder

为了考察粒子图像速度场仪 (PIV )的测量精度及分辨复杂流动结构的能力 ,对泊肃叶流动和圆柱绕流两种典型流动进行了测量 .将泊肃叶流动的速度廓线的测量值与分析解进行了对比 ,发现在测试区域内 90 %的测量值与分析解吻合良好 ,具有较高的精度 ,而近壁面区域由于速度偏振 ,测量值低于分析解 .在此基础上 ,利用PIV技术测量了Re为 5 0 0时圆柱绕流流动的主流区、圆柱两侧的剪切层 ,以及圆柱后的回流区和旋涡区的分布 ,验证了该技术非常适合于研究复杂的流动结构 .

In order to test the accuracy and resolution of complex vortex by particle image veloci- metry(PIV) ,velocity fields of poisoeulie flow and flow around a circular cylinder were measured. Comparison between the measured velocity profile and analytical solution of poisoeullie flow shows that good agreement was found within the 90% measured region, while the former was lower than the latter near the wall because of velocity polarization. Further measurement of flow around a circular cylinder at Re =500 provided the distribution area of main flow, shear layer flow, recirculated flow and vortex. The results validate that PIV is well suitable to investigate complex flow pattern.