同轴旋转倒置圆台环隙间流动特性分析

针对同轴旋转倒置圆台环隙间流体复杂流动问题, 对其环隙间流动特性进行了实验研究。重点进行染色液流动显示实验和PIV流场测速实验, 对实验结果做定性及定量分析, 研究内筒转速和环隙宽度对环隙间流动特性的影响。染色液流动显示实验和PIV流场测速实验分别定性和定量地展现了环隙间螺旋涡的产生及变化过程。对不同内筒转速和环隙宽度下的螺旋涡涡心运动周期进行分析, 结果表明, 内筒转速升高, 周期减小；环隙宽度增大, 周期增大。运用瞬时流动和时均流场解析了环隙间螺旋涡运动产生机制, 探究内筒转速和环隙宽度对3种雷诺应力大小的影响与分布情况。内筒转速变化, 雷诺径向正应力始终最大；环隙宽度变化, 雷诺切应力始终最小。 

Interannular flow characteristics of coaxial rotational conical cylinder

In order to solve the problem of complex flow between annulus of coaxial rotating conical cylinders, the flow characteristics of fluid between annular spaces were studied experimentally. Experimental studies were carried out for the complex flow characteristics of fluid between annulus of coaxial rotating conical cylinders. Emphasis was placed on staining fluid visualization experiment and PIV flow field measurements. The experimental results were analyzed qualitatively and quantitatively concerning the effects of rotating speed and annular width on interannular flow characteristics. Staining fluid visualization experiment and PIV flow field speed measurement experiment displayed the generation and variation of interannular spiral vortices qualitatively and quantitatively respectively. The period of motion of spiral vortex core under different inner cylinder speed and annulus width was analyzed. The results reveal that the period of motion decreases with the increase of inner cylinder speed, and the period of motion increases with the increase of annulus width. Instantaneous and time-averaged flow field were checked to analyze the mechanism of interannular spiral vortex motion and generation. The influence of inner cylinder speed and annulus width on three kinds of Reynolds stress and their distribution were studied. The radial normal Reynolds stress is always the largest when the inner cylinder speed is variable, and the Reynolds shear stress stays minimum when the annular width changes.