斜出口合成射流组流场特性PIV实验研究

提出了斜出口合成射流组的概念，应用PIV相位锁定技术对典型单缝、双缝和三缝斜出口合成射流组非定常流场结构进行了测试，并对出口间距比参数变化对斜出口合成射流组沿壁面的动量输运影响特性进行了探讨。结果表明：三缝斜出口合成射流组具有更强的沿壁面动量输运特性，具有更高的合成射流激励器能量利用效率。相邻射流出口间距比是影响斜出口合成射流组动量输运的重要参数，研究结果指出当间距比S/H＝3．0时，斜出口合成射流组具有较强的沿壁面动量输运特性。

PIV study on the flow field characteristics of beveled orifices synthetic jet arrays

As an important part of the formation of synthetic jet,the design and performance of synthetic jet actuator determine the field and effect of applications of the synthetic jet.How to design it efficiently with low energy consumption to obtain high control efficiency would be the key of synthetic jet applied in active flow control.Based on the study of single beveled orifice syn-thetic jet actuator,the concept of beveled orifices synthetic jet arrays is proposed.The unsteady flow structure of the typical single slit,double slit,the three slit beveled orifices synthetic jet ar-rays were tested with the application of PIV phase-locking technology.And the impact of orifices spacing ratio variation on momentum transport of beveled orifices synthetic j et arrays along the wall was studied.The results showed that,compared with the single slit and double slit,a strong vortex structure and wall-attached jet were formed around the three slit beveled orifices, and the synthetic jet had stronger tangetial velocity distribution along the wall.The flow along the wall was closer to the wall in the three slit beveled orifices,and prone to introduce the high momentum of the fluid in the main flow into the boundary layer at the bottom,thereby increas-ing the underlying energy distribution of the boundary layer.The momentum transport proper-ties of beveled orifices synthetic j et arrays are mainly from the induced effect of vortex and wall-attached jet effect along the wall,and also the flow velocity gradient after coupling of the two effects.Jet orifices spacing ratio is an important parameter affecting the momentum transport of synthetic jet arrays.When the jet spacing ratio is small,the opposite direction of flow velocity gradient difference between the vortex induction and wall-attached j et would be affected by the impact of jet from the first beveled orifice,which will weaken the vortex strength around the sec-ond beveled orifice.Thereby the velocity gradient difference of the flow will be reduced after cou-pling of the vortex and wall-attached jet,which will weaken the induction between the vortex and wall- attached j et .The research results indicated that the beveled orifices synthetic j et arrays will have stronger transporting momentum along the wall when the spacing ratio is 3 .0 .