不同出口倾角合成双射流流动特性及边界层控制

Flow characteristic of a dual synthetic jets actuator with different beveled exit and boundary layer control

关键词:  合成双射流激励器  边界层  流动控制  数值模拟

Key words:  Dual synthetic jets actuator  Boundary layer  Flow control  Numerical simulation

摘要:

基于合成双射流全流场计算模型———X-L模型,对不同出口倾角合成双射流的流动特性进行了数值研究。平直出口合成双射流激励器工作时,合成双射流在出口下游相互作用融合成一股射流,且合成双射流间有"自给"现象的发生;倾斜出口合成双射流激励器工作时,在激励器出口下游会形成一股沿壁面的流动,该壁面流可以对周围流体进行有方向的能量和质量输送;随着激励器出口倾斜角度的增大,合成双射流间"自给"现象减弱,沿壁面流速度增大。然后,对不同出口倾角合成双流激励器进行边界层流动控制进行了初步研究。结果显示,合成双射流激励器可控制边界层流动,通过改变激励器出口倾角可以实现对边界层内速度型"饱和"程度的控制。

Abstract:

Based on a whole flow field computational model for dual synthetic jet X-L model,numerical computations were performed to get the flow characteristic of the synthetic jet with different exit slot.For the conventional dual synthetic jet actuator,in the near field downstream of the exit slot,the two jets interacted with each other and merged into a single jet.Meanwhile,there was a phenomenon of "self-support" between the dual synthetic jets.When the beveled synthetic jet actuator worked,there formed a string of flow along the wall which chould be used to horizontally transmit the energy and mass flux of the fluid near the dual synthetic jet actuator.As the degree of the beveled orifice increased,"self-support" between the dual synthetic jets decreased and the flow along the wall swelled.The effect of the jet to the boundary flow control was studied as well.The results show that the dual synthetic jet can be used to control the flow of the boundary layer,and by changing the bevel of the exit,so as to control the velocity profile of the boundary.