Characteristics of Instabilities and Transition Processes of the Flow between a Rotating Disk and the Casing
Characteristics of Instabilities and Transition Processes of the Flow between a Rotating Disk and the Casing
复制标题
转盘与套管间流动的不稳定性特征及过渡过程
DOI：
10.1299/kikaib.54.1236
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Nobushige Teraji
中科院分区：
文献类型：
--
作者：
M. Itoh;Yutaka Yamada;H. Nagata;Nobushige Teraji
本文对旋转圆盘与机匣间流动的不稳定性特征及向湍流的转变过程进行了实验研究。对速度脉动的谱分析表明，在较大间隙比（s/R=0.080）的情况下，旋转盘上边界层流动的无粘不稳定性开始于局部雷诺数ReL（=r2ω/v）约为8×104，这与我们以前的理论计算结果一致。旋转盘附近的流动的可视化显示，两种不同类型的不稳定性发生在任何间隙比测试（s/R=0.016 <$0.160）。据信，其中一种是粘性类型，另一种是非粘性类型。这些不稳定性的特征进行比较与预测的线性稳定性分析。从速度功率谱的角度，阐明了两种不同间隙比（s/R=0.080，0.016）下湍流的转变过程。
The characteristics of instabilities and the transition processes to turbulence are studied experimentally for the flow between a rotating disk and its casing. The spectral analyses of the velocity fluctuations show that, in the case of a larger clearance ratio (s/R=0.080), an inviscid instability of the boundary layer flow on the rotating disk starts at the local Raynolds number ReL(=r2ω/ν) of about 8×104, which is in good agreement with that obtained theoretically in our previous work. Visualization of the flow near the rotating disk reveals that two different types of instabilities occur at any clearance ratio tested (s/R=0.016∼0.160). It is believed that one of these is a viscous type and the other is an inviscid type. The characteristics of these instabilities are compared with those predicted by a linear stability analysis. The transition processes to tubulence are clarified for two different clearance ratios (s/R=0.080, 0.016) in view of the velocity power spectrum.