摘要
数值研究了合成射流控制高负荷压气机叶栅非定常流动分离的效果及机理。结果表明,激励频率、幅值是影响合成射流控制效果的重要参数,当激励频率为最优值、幅值大于某一阈值时,叶栅时均总压损失系数最大降低40.3%,静压升系数提高12.1%。合成射流的动量注入显著增大了激励缝下游流场的湍流剪切应力,使得剪切层内的速度脉动增强,在宏观上表现为近壁区域与主流流体间的动量交换得到加强,这是非定常流动分离得到抑制的主要原因。
Numerical simulation is performed to investigate the effect and mechanism of synthetic jet on flow separation control in a highly-loaded compressor cascade.Results show that the actuation frequency and jet amplitude are key parameters for control effect.When the forcing frequency is close to the optimal value and the jet amplitude is above a threshold value,the time-averaged total pressure loss coefficient drops at most 40.3%and the static pressure coefficient increases by 12.1%.The turbulent shear stress downstream of the excitation slot is significantly enlarged with momentum injection,which contributes to increase the velocity fluctuation level in the shear layer.In macro presentation,the momentum exchange between the near wall region and the mainstream is surprisingly strengthened.That is the main reason that unsteady flow separation is effectively suppressed.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2016年第10期2076-2083,共8页
Journal of Engineering Thermophysics
关键词
高负荷压气机叶栅
合成射流
非定常流动分离
流动控制
激励参数
highly-loaded compressor cascade
synthetic jet
unsteady flow separation
flow control
actuation parameters
