Fluid Dynamics of a Bistable Diverter Under Ultrasonic Excitation-Part I: Performance Characteristic
Fluid Dynamics of a Bistable Diverter Under Ultrasonic Excitation-Part I: Performance Characteristic
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超声波激励下双稳态分流器的流体动力学第一部分：性能特点
DOI：
10.1115/1.4050083
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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
本文研究了一种进口喷嘴马赫数Mn=0.3，工作压力比Pr = 1.1的超声驱动双稳态流体分流器。第一部分考察了与激励幅度、频率、所需能量、开关时间和进口总压力等非量纲参数相关的开关特性。结果表明，在湍流射流马赫数高达Mn=0.3时，为了促进切换，必须激发St = 0.45的射流优先模式，这与以前报道的类似装置的层流射流操作不同。对于参考情况，开关时间为1.2 ms，表明振荡频率高达500 Hz。第二部分是结合实验和数值研究，使用大涡模拟（LES）检查自由剪切层中触发的不稳定模式，并使用粒子图像测速（PIV）可视化流场。
This paper investigates an ultrasonically driven bistable fluidic diverter at inlet nozzle Mach numbers of up to Mn=0.3 and operating pressure ratios of up to Pr = 1.1. Part I examines the switching characteristics with respect to nondimensional parameters of excitation amplitude, frequency, required energy, switching time and inlet total pressure. It is shown that to promote switching at turbulent jet Mach numbers of up to Mn=0.3 it is necessary to excite a jet preferred mode of St = 0.45 which differs from previously reported laminar jet operation of the similar device. For the reference case the switching time amounts to 1.2 ms suggesting oscillation frequencies of up to 500 Hz. Part II is a combined experimental and numerical study that examines the triggered instability modes in the free shear layer using large eddy simulations (LES) and visualizes the flow field using Particle Image Velocimetry (PIV).