Fluid Dynamics of a Bistable Diverter Under Ultrasonic Excitation-Part II: Flow Visualization and Fundamental Mechanisms
Fluid Dynamics of a Bistable Diverter Under Ultrasonic Excitation-Part II: Flow Visualization and Fundamental Mechanisms
复制标题
超声波激励下双稳态分流器的流体动力学 - 第二部分：流动可视化和基本机制
DOI：
10.1115/1.4050084
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Mair M
中科院分区：
文献类型：
--
作者：
Mair M
采用大涡模拟（LES）和粒子成像测速（PIV）技术研究了主动控制射流装置的切换机理和流动物理特性。本文考虑的流体装置使用固有流动不稳定性的声激励来控制射流的运动。在优选的频率下的声激励示出产生高的饱和振幅，从而形成大的旋涡结构，不进行配对。进一步研究了包括剪切层不稳定性在内的基本流动特征，以解释为什么触发切换过程的激励模式随着雷诺数的增加从基于剪切层的模式（）变为射流孔模式（）。
The switching mechanism and underlying flow physics of an actively controlled fluidic device are investigated using both large eddy simulation (LES) and particle imaging velocimetry (PIV). The fluidic device considered herein uses acoustic excitation of inherent flow instabilities to control the movement of the jet. Acoustic excitation at the preferred frequency is shown to yield high saturation amplitudes resulting in the formation of large vortical structures that do not undergo pairing. Basic flow features including the shear layer instabilities are further examined to explain why the excitation mode that triggers the switching process changes from a shear layer-based mode () to a jet orifice mode () as the Reynolds number increases.