为了进一步提高等离子体流动控制的作用能力,采用a-A1203为电介质材料的介质阻挡放电等离子体激励器,进行了在不同来流风速、不同攻角下等离子体抑制NACA0015翼型边界层流动分离的烟线流显示实验。实验结果表明:等离子体激励可以有效抑制低流速、大攻角下的流动分离;在来流风速为35m/s时,等离子体作用后翼型的失速攻角提高1.5°,等离子体抑制流动分离的效果随着攻角的增加变弱;在攻角为20.5°、来流风速30,--44m/s时,等离子体对流动的控制随着来流风速呈现“变弱一增强一变弱”的趋势,等离子体激励器在翼型上的位置非常重要,越接近分离点作用效果最好;来流风速60m/s时,等离子体仍能有效抑制翼型的失速分离,升力增加31.1%,阻力减少27.8%。
To improve plasma aerodynamic actuator, through smoke wire visualization experiments, we investigated the performance of a dielectric barrier discharge (DBD) plasma actuator on controlling the plasma flow separation of NA- CA0015 airfoil at different free-stream velocities and different angles of attack. The actuator uses a-A1203 as its dielectric material. The experimental results show that plasma actuation can effectively suppress the flow separation at low free-stream velocities and high attack angles. When the free-stream velocity is 35 m/s, plasma actuation increases the stall angle by 1.5°, while the suppressing effect of plasma flow separation decreases with the increase of the angle of attack. When the angle of attack is 20.5° and the free-stream velocity within 30-44 m/s, the plasma flow control shows a ten- dency of "weakening-enhancing-weakening" with the increase of free-stream velocity. The location of the plasma actuator on the airfoil is found to be crucial for suppressing flow separation; better effect is obtained when the plasma actuator is close to the separation point. The plasma is able to suppress the separated flow at the free-stream velocity of 60 m/s, with an increase in lift force by 31.1% and a decrease in drag force by 27.8%.