气固两相圆柱绕流近场特性的实验研究

采用PIV实验技术对气固两相圆柱绕流的近场特性进行了研究。通过对图像进行数据处理，发现Stokes数为0.97的颗粒与涡结构的相互作用最为强烈，在尾迹中心区流向平均速度较低，且变化幅度较大，但脉动速度和湍动能较高。而较大Stokes数的颗粒不易受涡结构的影响，流向平均速度在尾迹中心区的分布也较平缓，但脉动速度和湍动能在两侧的剪切层区较高。各种颗粒在圆柱绕流回流区的脉动速度和湍动能都要高于近尾迹区的相应值，这为颗粒的混合和稳定燃烧等提供了有利的条件。关键词：；；；

Experimental Study of Flow Characteristics in the Near Field of Gas-Solid Two-phase Circular Cylinder Wakes

The experimental technology based on PIV (Particle Image Velocimetry) was used to study flow characteristics in the near field of gas-solid two-phase cylinder wakes. By data processing of many images obtained in the experiments, it is found that the particles at the Stokes number of 0.97 have the strongest interaction with vortex structures. They also have the lower stream wise mean velocity with larger variation, the higher fluctuating velocity and the higher turbulent kinetic energy in the center region of the wake. However, the particles at the larger Stokes numbers are influenced less by vortex structures. The distributions of their stream wise mean velocity are flatter in the center region of the wake, but their fluctuating velocity and turbulent kinetic energy are higher in the regions of two-side shear layers. For all particles, the fluctuating velocity and turbulent kinetic energy in the recirculating area are higher than that in the near wake area, which provides advantaged conditions for particle mixing and stable combustion.